Peritoneal washing cytology status as a crucial prognostic determinant in patients with localized pancreatic ductal adenocarcinoma who underwent curative-intent resection following preoperative chemoradiotherapy.

BACKGROUND: Prognostic implications of peritoneal washing cytology (CY) in patients with localized pancreatic ductal adenocarcinoma (PDAC) undergoing surgical resection following preoperative chemoradiotherapy (CRT) remain unclear. This study aimed to elucidate the prognostic significance and predictors of a positive CY status (CY+) after preoperative CRT. METHODS: Clinical data from 141 patients with localized PDAC who underwent curative-intent resection after preoperative CRT were retrospectively analyzed to examine the association between CY+ and clinicopathological factors and survival. RESULTS: CY+ was observed in six patients (4.3%). The CY+ group exhibited significantly higher preoperative serum levels of CA19-9 and a substantially greater incidence of tumor location in the pancreatic body or tail, along with pathological invasion to the anterior pancreatic capsule, than the CY- group. The CY+ group had a significantly higher incidence of peritoneal recurrence compared with the CY- group (83.3% vs. 18.5%, p = 0.002). Overall survival (OS) and recurrence-free survival (RFS) after surgery were significantly shorter in the CY+ group than in the CY- group (CY+ vs. CY-: 18.3 vs. 46.2 months, p = 0.001, and 8.9 vs. 17.7 months, p = 0.009, respectively). Multivariate analyses identified CY+ as an independent prognostic factor for worse OS (hazard ratio 5.00, 95% confidence interval 1.03-12.31) and RFS (hazard ratio 2.58, 95% confidence interval 1.04-6.43). Local invasion grade on imaging before CRT, limited histological response to CRT, and absence of adjuvant chemotherapy were independent predictors of worse OS and RFS. CONCLUSION: Despite the relatively low incidence of CY+ after preoperative CRT, it emerged as an independent prognostic factor in patients with localized PDAC undergoing curative-intent resection following preoperative CRT.

A comprehensive and longitudinal evaluation of the different populations of lymphoid and myeloid cells in the peripheral blood of patients treated with chemoradiotherapy for head and neck cancer.

BACKGROUND: Immunotherapy provided significant survival benefits for recurrent and metastatic patients with head and neck cancer. These improvements could not be reproduced in patients treated with curative-intent chemoradiotherapy (CRT) and the optimal radio-immunotherapy (RIT) concepts have yet to be designed. Exploration and analysis of the pre-therapeutic immune status of these patients and the changes occurring during the treatment course could be crucial in rationally designing future combined treatments. METHODS: Blood samples were collected from a cohort of 25 head and neck cancer patients treated with curative-intended (C)-RT prior to therapy, after the first week of treatment, and three months after treatment completion. Peripheral blood mononuclear cells (PBMCs) or all nucleated blood cells were isolated and analyzed via flow cytometry. RESULTS: At baseline, patients showed reduced monocyte and lymphocyte counts compared to healthy individuals. Although overall CD8+ T-cell frequencies were reduced, the proportion of memory subsets were increased in patients. Radiotherapy (RT) treatment led to a further increase in CD8+ effector memory T-cells. Among myeloid populations, tumor-promoting subsets became less abundant after RT, in favor of pro-inflammatory cells. CONCLUSION: The present study prospectively demonstrated a complex interplay and distinct longitudinal changes in the composition of lymphocytic and myeloid populations during curative (C)-RT of head and neck cancer. Further validation of this method in a larger cohort could allow for better treatment guidance and tailored incorporation of immunotherapies (IT) in the future.

The role of prehabilitation in HNSCC patients treated with chemoradiotherapy.

BACKGROUND: Radiotherapy (RT) is used in head and neck squamous cell carcinoma (HNSCC) with excellent effectiveness, but it is burdened by important side effects, which may negatively impact patients' quality of life (QoL). In particular when associated with chemotherapy (CT), that has a radiosensitising effect (and its own toxicities), it is responsible for several adverse events, causing social discomfort and lower QoL, in patients who are already experiencing several tumor-related discomforts. Prehabilitation is a healthcare intervention consisting of several specialist visits prior to the start of treatment, with the aim of improving the patient's health status, resolving symptoms that interfere with treatment and impact QoL, and finally to better avoid or overcome complications. Of all cancer patients, HNSCC patients are among those who could benefit most from prehabilitation, both because of the high number of symptoms and toxicities and their difficult management. Despite this and the emerging data, prehabilitation is not often considered for the majority of patients undergoing (C)RT. In this review, we tried to understand what are the main areas in which interventions can be made prior to the (C)RT start, the possible side effects of the treatment, the effectiveness in their prevention and management, and the impact that prehabilitation may have in adherence to therapy and on the principal survival outcomes, providing important guidance for the planning of future studies. EVIDENCES AND CONCLUSIONS: Although there is no strong data evaluating multidisciplinary prehabilitation strategies, evidence shows that optimizing the patient's health status and preventing possible complications improve the QoL, reduce the incidence and severity of adverse events, and improve treatment adherence. While cardiology prehabilitation is of paramount importance for all patients undergoing concomitant CRT in the prevention of possible side effects, the remaining interventions are useful independently of the type of treatment proposed. Geriatricians have a key role in both elderly patients and younger patients characterized by many comorbidities to comprehensively assess health status and indicate which treatment may be the best in terms of risk/benefit ratio. Collaboration between nutritionists and phoniatrics, on the other hand, ensures adequate nutritional intake for the patient, where possible orally. This is because optimizing both body weight and muscle mass and qualities has been shown to impact key survival outcomes. Finally, HNSCC patients have the second highest suicide rate, and the disease has side effects such as pain, dysfiguration, and sialorrhea that can reduce the patient's social life and create shame and embarrassment: A psychological intake, in addition to the usefulness to the patient, can also provide current support to caregivers and family members. Therefore clinicians must define a personalized pathway for patients, considering the characteristics of the disease and the type of treatment proposed, to optimize health status and prevent possible side effects while also improving QoL and treatment adherence.

Late dental and bone alterations in patients after orbital rhabdomyosarcoma treatment.

PURPOSE: Orbital rhabdomyosarcoma is a rare soft tissue sarcoma in childhood but with a good prognosis. Treatment usually includes surgery, chemotherapy, and radiotherapy. This study aimed to evaluate long-term alterations in teeth and cranial bones in children, adolescents, and young adults after oncologic treatment for childhood orbital rhabdomyosarcoma. METHOD: This was a cross-sectional study that evaluated patients treated for orbital rhabdomyosarcoma between 1988 and 2011. Demographic, clinical, and treatment data were collected during the study period; also, panoramic radiographs, cephalometric study, and photographs of the face were taken. RESULTS: Eight long-term survivors were studied. Of those, 50% were male, 75% had less than 5 years of treatment, and 88% had only one of the orbits affected by the tumor. Regarding treatment, 50% received 50.4 Gy of radiotherapy in the orbit; the chemotherapy included vincristine, actinomycin D, and cyclophosphamide in 75% of the cases and also ifosfamide and etoposide in 25%. The children presented craniofacial alterations, mainly when radiotherapy occurred between 0 and 5 years old (p = 0.01). The mandibles also showed dental alterations, probably due to chemotherapy. CONCLUSION: In conclusion, orbital RMS patients treated with chemoradiotherapy, important dental, and facial bone alterations were found. The most significant were in the maxilla and close to the irradiation field. Dental and mandibular bone alterations were also found, indicating the probable chemotherapy action, as this region was not included in the irradiation field.

Treatment strategies for elderly patients with locally advanced esophageal cancer: a systematic review and meta-analysis.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) followed by surgery remains a standard of care for resectable esophageal cancer (EC), and definitive chemoradiotherapy (dCRT) is an alternative for unresectable diseases. However, it is controversial for the use of the two aggressive regimens in elderly patients. METHODS: We systematically searched multiple databases for studies comparing overall survival (OS) and/or progression-free survival (PFS) between dCRT and surgery (nCRT + surgery or surgery alone) or between dCRT and radiotherapy (RT) alone in elderly patients (age ≥ 65 years) until March 28, 2024. Statistical analysis was performed using random-effects model. RESULTS: Fourty-five studies with 33,729 patients were included. dCRT significantly prolonged OS (hazard ratio [HR] = 0.64, 95% confidence interval [CI]: 0.58-0.70) and PFS (HR = 0.67, 95% CI: 0.60-0.76) compared to RT alone for unresectable EC, and resulted in a worse OS compared to surgery for resectable cases (HR = 1.34, 95% CI: 1.23-1.45). Similar results of OS were also observed when the multivariate-adjusted HRs were used as the measure of effect (dCRT vs. RT alone: HR = 0.65, 95% CI: 0.58-0.73; dCRT vs. surgery: HR = 1.49, 95% CI: 1.28-1.74). Subgroup analyses according to age group (≥ 70, ≥ 75, or ≥ 80 years), study design, study region, histological type, radiation field, chemotherapy regimen revealed comparable results. CONCLUSIONS: nCRT + surgery is likely a preferred strategy for elderly patients with good physiological conditions; and dCRT is a better alternative for unresectable cases. Advanced age alone does not appear to be a key predictor for the tolerability of the two aggressive treatments.

Decreased plasma gelsolin fosters a fibrotic tumor microenvironment and promotes chemoradiotherapy resistance in esophageal squamous cell carcinoma.

BACKGROUND: Stromal fibrosis is highly associated with therapeutic resistance and poor survival in esophageal squamous cell carcinoma (ESCC) patients. Low expression of plasma gelsolin (pGSN), a serum abundant protein, has been found to correlate with inflammation and fibrosis. Here, we evaluated pGSN expression in patients with different stages of cancer and therapeutic responses, and delineated the molecular mechanisms involved to gain insight into therapeutic strategies for ESCC. METHODS: Circulating pGSN level in ESCC patients was determined by enzyme-linked immunosorbent assay analysis, and the tissue microarray of tumors was analyzed by immunohistochemistry staining. Cell-based studies were performed to investigate cancer behaviors and molecular mechanisms, and mouse models were used to examine the pGSN-induced tumor suppressive effects in vivo. RESULTS: Circulating pGSN expression is distinctively decreased during ESCC progression, and low pGSN expression correlates with poor therapeutic responses and poor survival. Methylation-specific PCR analysis confirmed that decreased pGSN expression is partly attributed to the hypermethylation of the GSN promoter, the gene encoding pGSN. Importantly, cell-based immunoprecipitation and protein stability assays demonstrated that pGSN competes with oncogenic tenascin-C (TNC) for the binding and degradation of integrin αvß3, revealing that decreased pGSN expression leads to the promotion of oncogenic signaling transduction in cancer cells and fibroblasts. Furthermore, overexpression of pGSN caused the attenuation of TNC expression and inactivation of cancer-associated fibroblast (CAF), thereby leading to tumor growth inhibition in mice. CONCLUSIONS: Our results demonstrated that GSN methylation causes decreased secretion of pGSN, leading to integrin dysregulation, oncogenic TNC activation, and CAF formation. These findings highlight the role of pGSN in therapeutic resistance and the fibrotic tumor microenvironment of ESCC.

Trends in the treatment of human papillomavirus-associated oropharyngeal carcinoma in Slovakia.

The optimal treatment of oropharyngeal cancer (OPC) associated with human papillomavirus (HPV) is currently a subject of clinical research. This questionnaire study investigated current trends in the treatment of HPV-associated (HPV+) OPC in Slovakia with the incorporation of deintensification of oncological treatment into routine clinical practice outside of clinical trials. The Slovak Cooperative Head and Neck Cancer Group (SCHNCG) developed a questionnaire aimed at identifying trends in the oncological treatment of HPV+ OPC intended for all radiation oncology (RO) facilities in Slovakia. Specialists in the field of RO responded to general questions about the character of their individual institutions as well as to 4 theoretical clinical scenarios (case reports) regarding the treatment of HPV+ OPC, focusing primarily on the applied dose of radiotherapy (RT), the extent of target volumes, and the type of concurrent chemotherapy (CHT). The questionnaire study involved 35 RO specialists from 14 institutions in Slovakia. Regarding primary chemoradiotherapy (CRT) in T1N1M0 HPV+ OPC, 16 respondents (45.7%) would consider de-escalation of the RT dose to <70 Gy. In the case of postoperative RT in pT1pN1M0 HPV+ OPC with negative resection margins (R0) and absent extracapsular extension (ECE), 4 physicians (11.4%) would consider de-escalation of the RT dose to <60 Gy in the tumor bed area, while the majority of the treating specialists (n=19, 54.3%) would omit concurrent CHT. In the case of primary RT in elderly patient with T2N1M0 HPV+ OPC, the same number of physicians (n=16, 45.7%) would consider de-escalation of the RT dose to <70 Gy, and 14 respondents (40.0%) would completely omit CHT. In a high-risk patient with T2N3M0 HPV+ OPC with a complete response after 3 cycles of induction chemotherapy (iCHT), none of the respondents would indicate a reduction in the RT dose to the area of the original tumor and lymphadenopathy to <60 Gy. The doses and extent of irradiated volumes in the treatment of HPV+ OPC in Slovakia vary among different institutions. The tendency to de-escalate RT doses and reduce doses of concurrent systemic therapy in Slovakia is high and there was also an observed trend to reduce the extent of radiation treatment fields.

Comparing long-term efficacy and safety of GP versus TPF sequential chemoradiotherapy for locoregionally advanced nasopharyngeal carcinoma: a propensity score-matched analysis.

PURPOSE: To evaluate the long-term efficacy and safety of GP and TPF sequential chemotherapy regimens in patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC). METHODS: From 2005 to 2016, a total of 408 LA-NPC patients treated with GP or TPF sequential chemoradiotherapy were retrospectively included. Propensity Score Matching (PSM) was employed to balance the baseline variables. Survival outcomes and acute toxicities were compared between both groups. RESULTS: A total of 230 patients were selected by 1:1 PSM. At a median follow-up of 91 months, no significant differences were observed between the matched GP and TPF groups regarding 5-year overall survival, progression-free survival, distant metastasis-free survival, and locoregionally relapse-free survival (83.4% vs. 83.4%, P = 0.796; 75.6% vs. 68.6%, P = 0.301; 86.7% vs. 81.1%, P = 0.096; and 87.4% vs. 87.2%, P = 0.721). Notable disparities in adverse effects were identified, with higher incidences of grade 3/4 thrombocytopenia in the GP group while grade 3/4 leukopenia and neutropenia in the TPF group. Though not recorded in our cohort, combined with the FAERS database, thrombotic adverse reactions are a concern for the GP regimen, while the TPF regimen requires vigilance for life-threatening adverse reactions such as septic shock, acute respiratory distress syndrome, and laryngeal edema. CONCLUSION: No significant difference in long-term outcomes was observed between the GP and TPF sequential chemotherapy regimens for LA-NPC. Differences in adverse effects should be noted when choosing the regimen.

Regimens combining radiation and immunotherapy for cancer: latest updates from 2024 ASCO Annual Meeting.

Combination of immunotherapy with radiotherapy is under active investigation. The PACIFIC trial firmly established the treatment paradigm of consolidation immunotherapy following definitive chemoradiotherapy, inspiring a series of similar or exploratory combination regimens. This summary highlighted six reports updated in the 2024 ASCO Annual Meeting.

Effect of primary tumor volume on survival of concurrent chemoradiotherapy in stage IV non-small cell lung cancer.

OBJECTIVE: To explore the survival effect of thoracic gross tumor volume (GTV) in three-dimensional (3D) radiotherapy for stage IV non-small cell lung cancer (NSCLC). METHODS: The data cases were obtained from a single-center retrospective analysis. From May. From 2008 to August 2018, 377 treatment criteria were enrolled. GTV was defined as the volume of the primary lesion and the hilus as well as the mediastinal metastatic lymph node. Chemotherapy was a platinum-based combined regimen of two drugs. The number of median chemotherapy cycles was 4 (2-6), and the cut-off value of the planning target volume (PTV) dose of the primary tumor was 63 Gy (30-76.5 Gy). The cut-off value of GTV volume was 150 cm3 (5.83-3535.20 cm3). RESULTS: The survival rate of patients with GTV <150 cm3 is better than patients with GTV ≥150 cm3. Multivariate Cox regression analyses suggested that peripheral lung cancer, radiation dose ≥63 Gy, GTV <150 cm3, 4-6 cycles of chemotherapy, and CR + PR are good prognostic factors for patients with stage IV non-small cell lung cancer. The survival rate of patients with GTV <150 cm3 was longer than patients with ≥150 cm3 when they underwent 2 to 3 cycles of chemotherapy concurrent 3D radiotherapy (p < 0.05). When performing 4 to 6 cycles of chemotherapy concurrent 3D radiotherapy, there was no significant difference between <150 cm3 and ≥150 cm3. CONCLUSIONS: The volume of stage IV NSCLC primary tumor can affect the survival of patients. Appropriate treatment methods can be opted by considering the volume of tumors to extend patients' lifetime to the utmost.

Persistent Lymph Node Metastases After Neoadjuvant Chemoradiotherapy for Rectal Cancer.

Importance: Patients with locally advanced rectal cancer and persistent lymph node metastases (PLNM) after neoadjuvant treatment are at high risk of developing locoregional and distant metastasis, yet optimal postsurgical treatment of these patients is limited. Objective: To analyze the association of PLNM with pretreatment clinical parameters, intensity of neoadjuvant treatment, and long-term oncological outcomes. Design, Setting, and Participants: This cohort study is a post-hoc analysis of 3 randomized clinical trials (Surgical Oncology Working Group of Germany [CAO], Radiological Oncology Working Group of Germany [ARO], and Working Group for Internal Oncology in the German Cancer Society [AIO]) conducted in Germany in 1994, 2004, and 2012 that included 1948 patients with locally advanced rectal cancer recruited between February 1995 and January 2018. Statistical analysis was conducted between September 2023 and February 2024. Exposures: Receiving preoperative fluorouracil-based chemoradiotherapy (CRT, comprising the preoperative group of CAO/ARO/AIO-94 and the control group of CAO/ARO/AIO-04), fluorouracil-based CRT plus oxaliplatin (experimental group of CAO/ARO/AIO-04), or total neoadjuvant treatment (TNT) with fluorouracil-based CRT plus oxaliplatin with induction or consolidation leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin chemotherapy within the CAO/ARO/AIO-12 trial. Main Outcome and Measures: The associations of PLNM with clinical parameters, intensity of neoadjuvant treatment, and cumulative incidences of LR, DM, and overall survival were assessed. Results: A total of 1888 patients (1333 male participants [70.6%]; median [range] age, 62 [19-84] years) with locally advanced rectal adenocarcinoma (clinical tumor stage 3 to 4 and/or clinically node-positive) treated within 3 consecutive clinical trials were analyzed. A total of 522 (29%) experienced PLNM; 378 had lymph node stage (ypN) 1 (20%) after neoadjuvant treatment (ypN) 1 (20%), and 174 had ypN2 (9%). Age, clinical T-stage, N-stage, grading, carcinoembryonic antigen levels, and time interval from completion of CRT to surgery were significantly associated with PLNM, whereas sex and tumor location were not. The percentage of patients with ypN2 stage was almost halved after TNT (18 of 293 patients [6%]) compared with patients treated with fluorouracil-based CRT (114 of 1009 patients [11.3%]; χ26 = 16.693; P = .01). After a median (IQR) follow-up of 54 (37-62) months, 5-year overall survival was 86.1% (95% CI, 83.9%-88.4%) for ypN0, 74.0% (95% CI, 83.9%-88.4%) for ypN1, and 43% for ypN2 (95% CI, 35.4%-52.2%) (P < .001). The 5-year cumulative incidences of locoregional and distant metastases were, respectively, 3% (95% CI, 2.1%-4.2%) and 20% (95% CI, 18%-23%) for ypN0, 6% (95% CI, 3.4%-8.8%) and 40% (95% CI, 34%-46%) for ypN1, and 19% (95% CI, 13%-26%) and 72% (95% CI, 63%-79%) for ypN2 (both P < .001). Conclusions and Relevance: In this cohort study, PLNM unmasked an unfavorable phenotype of rectal cancer at high risk for treatment failure. More aggressive adjuvant treatment might be considered; however, risk-adapted surveillance strategies and early recurrence-directed surgery, if feasible, are important strategies in this group of patients with CRT- and/or chemotherapy-resistant disease.

Radical chemoradiotherapy for superficial esophageal cancer complicated with liver cirrhosis.

Background: Although chemoradiotherapy is an effective treatment for esophageal cancer, its feasibility in esophageal cancer with cirrhosis remains largely unclear. Methods: We retrospectively studied 11 patients with superficial esophageal cancer with liver cirrhosis (Child-Pugh score ≤8) who underwent radical chemoradiotherapy from four centers, and the overall survival rate, local control rate and adverse events at 1 and 3 years were explored. Results: The median age of the included patients was 67 years (Inter-Quartile Range 60-75 years). Complete response was observed in most patients (n = 10, 90.9%), and the remaining patient was unevaluable. The 1- and 3-year overall survival and local control rates were 90.9% and 90.9%, and 72.7% and 63.6%, respectively. Hematotoxicity was a common adverse reaction, and seven patients developed radiation esophagitis, with grade 3-4 observed in two cases. All cases of radiation dermatitis (n = 4) and radiation pneumonia (n = 2) were grade 1-2. Gastrointestinal bleeding occurred in two patients, including one with grade 1-2 bleeding, and one died. Conclusion: Radical chemoradiotherapy is a potential treatment option for patients with superficial esophageal cancer complicated with cirrhosis. However, it can increase the risk of bleeding, which warrants prompt recognition and intervention.

A retrospective evaluation of therapeutic efficacy and safety of chemoradiotherapy in older patients (aged ≥ 75 years) with limited-disease small cell lung cancer: insights from two institutions and review of the literature.

BACKGROUND: The standard treatment for patients in good general condition with limited-disease small cell lung cancer (LD-SCLC) is concurrent platinum/etoposide chemotherapy and thoracic radiotherapy (TRT). However, the efficacy and safety of chemoradiotherapy (CRT) in older patients with LD-SCLC has not been fully explored; moreover, the optimal treatment for this patient group remains unclear. This study aimed to investigate the feasibility and efficacy of CRT in older patients with LD-SCLC. PATIENTS AND METHODS: From April 2007 to June 2021, consecutive older patients (aged ≥ 75 years) with stage I to III SCLC who received concurrent or sequential CRT at two institutions were retrospectively evaluated for efficacy and toxicity of CRT. RESULTS: A total of 32 older patients underwent concurrent (n = 19) or sequential (n = 13) CRT for LD-SCLC. The median ages of the patients in the concurrent and sequential CRT groups were 77 (range: 75-81) years and 79 (range: 76-92) years, respectively. The median number of chemotherapeutic treatment cycles was four (range, 1-5), and the response rate was 96.9% in all patients (94.7% in concurrent and 100% in sequential CRT groups). The median progression-free survival (PFS) and median overall survival (OS) for all patients were 11.9 and 21.1 months, respectively. The median PFS was 13.0 and 9.0 months in the concurrent CRT and sequential CRT groups, respectively, with no statistically significant difference (p = 0.67). The median OS from the initiation of CRT was 19.2 and 23.5 months in the concurrent and sequential CRT groups, respectively (p = 0.46). The frequencies of Grade ≥ 3 hematological adverse events were as follows: decreased white blood cell count, 20/32 (62.5%); decreased neutrophil count, 23/32 (71.9%); anemia, 6/32 (18.8%); decreased platelet count, 7/32 (21.9%); and febrile neutropenia, 3/32 (9.4%). Treatment-related deaths occurred in one patient from each group. CONCLUSIONS: Although hematological toxicities, particularly reduced neutrophil count, were severe, CRT showed favorable efficacy in both concurrent and sequential CRT groups. However, concurrent CRT may not be feasible for all older patients with LD-SCLC; accordingly, sequential CRT may be considered as a treatment of choice for these patients. Further prospective trials are warranted to identify optimal treatment strategies for this patient group.

Efficacy and safety of MR-guided adaptive simultaneous integrated boost radiotherapy to primary lesions and positive lymph nodes in the neoadjuvant treatment of locally advanced rectal cancer: a randomized controlled phase III trial.

BACKGROUND: In locally advanced rectal cancer (LARC), optimizing neoadjuvant strategies, including the addition of concurrent chemotherapy and dose escalation of radiotherapy, is essential to improve tumor regression and subsequent implementation of anal preservation strategies. Currently, dose escalation studies in rectal cancer have focused on the primary lesions. However, a common source of recurrence in LARC is the metastasis of cancer cells to the proximal lymph nodes. In our trial, we implement simultaneous integrated boost (SIB) to both primary lesions and positive lymph nodes in the experimental group based on magnetic resonance-guided adaptive radiotherapy (MRgART), which allows for more precise (and consequently intense) targeting while sparing neighboring healthy tissue. The objective of this study is to evaluate the efficacy and safety of MRgART dose escalation to both primary lesions and positive lymph nodes, in comparison with the conventional radiotherapy of long-course concurrent chemoradiotherapy (LCCRT) group, in the neoadjuvant treatment of LARC. METHODS: This is a multi-center, randomized, controlled phase III trial (NCT06246344). 128 patients with LARC (cT3-4/N+) will be enrolled. During LCCRT, patients will be randomized to receive either MRgART with SIB (60-65 Gy in 25-28 fractions to primary lesions and positive lymph nodes; 50-50.4 Gy in 25-28 fractions to the pelvis) or intensity-modulated radiotherapy (50-50.4 Gy in 25-28 fractions). Both groups will receive concurrent chemotherapy with capecitabine and consolidation chemotherapy of either two cycles of CAPEOX or three cycles of FOLFOX between radiotherapy and surgery. The primary endpoints are pathological complete response (pCR) rate and surgical difficulty, while the secondary endpoints are clinical complete response (cCR) rate, 3-year and 5-year disease-free survival (DFS) and overall survival (OS) rates, acute and late toxicity and quality of life. DISCUSSION: Since dose escalation of both primary lesions and positive nodes in LARC is rare, we propose conducting a phase III trial to evaluate the efficacy and safety of SIB for both primary lesions and positive nodes in LARC based on MRgART. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov with the Identifier: NCT06246344 (Registered 7th Feb 2024).

Oncologic Outcome of Patients With Pathologic T0 Esophageal Squamous Cell Carcinoma After Neoadjuvant Chemoradiotherapy.

BACKGROUND AND OBJECTIVE: To investigate the oncologic outcomes of patients with esophageal squamous cell carcinoma (ESCC) who have achieved a pathologic complete response (pCR) of the primary tumor (ypT0) after neoadjuvant chemoradiotherapy (NCRT). METHODS: Patients with thoracic ESCC who underwent scheduled NCRT followed by surgery at our hospital between January 2010 and December 2022 were retrospectively analyzed. Only patients with ypT0 disease were enrolled in this study. RESULTS: A total of 118 patients were ultimately enrolled in this study. Ninety-two patients achieved pCR in the primary tumor and lymph nodes (ypT0N0), while 26 patients had residual metastatic disease in 52 lymph nodes (ypT0N+). Forty-five of the 52 lymph nodes with residual tumors were abdominal lymph nodes. Positive lymph nodes were more often observed in patients with tumors located in the lower third of the esophagus. The 1-, 3-, and 5-year overall survival (OS) rates for the entire study group were 96.5%, 79.5%, and 77.1%, and the 1-, 3-, and 5-year disease-free survival (DFS) rates were 90.5%, 76.8%, and 69.0%, respectively. According to multivariate analyses, pN classification was an independent predictor of both OS and DFS (P < 0.05), while sex and cT classification were also found to be independent prognostic factors for DFS (P < 0.05). CONCLUSIONS: Residual nodal metastatic disease in patients with ypT0 ESCC after NCRT was more often found in the abdominal lymph nodes. pN classification was an independent predictor of both OS and DFS for ypT0 ESCC patients after NCRT.

Zinc finger protein 263 promotes colorectal cancer cell progression by activating STAT3 and enhancing chemoradiotherapy resistance.

Zinc finger protein 263 (ZNF263) is frequently upregulated in various tumor types; however, its function and regulatory mechanism in colorectal cancer (CRC) have not yet been elucidated. In this study, the expression of ZNF263 was systematically examined using data from The Cancer Genome Atlas database and samples from patients with CRC. The results indicated that high expression of ZNF263 in CRC tissues is significantly associated with tumor grade, lymph node metastasis and disant metastasis. Additionally, overexpression of ZNF263 significantly promoted the proliferation, invasion, migration, and epithelial-mesenchymal transition of CRC cells, while also increasing signal transducer and activator of transcription 3 (STAT3) expression and mRNA stability. Conversely, knockdown of ZNF263 inhibited the malignant behavior of CRC cells and decreased STAT3 expression and mRNA stability. Further mechanism studies using chromatin immunoprecipitation (CHIP) and luciferase assays verified that ZNF263 directly binds to the STAT3 promoter. Rescue experiments demonstrated that the knockdown or overexpression of STAT3 could significantly reverse the effects of ZNF263 on CRC cells. Additionally, our study found that overexpression of ZNF263 enhanced the resistance of CRC cells to the chemoradiotherapy. In summary, this study not only elucidated the significant role of ZNF263 in CRC but also proposed novel approaches and methodologies for the diagnosis and treatment of this malignancy.

AB038. Establishing a reliable semi-automated segmentation method for assessing chemoradiotherapy effects on the non-tumoral brain.

BACKGROUND: Current voxel-based morphometry (VBM) studies of chemoradiotherapy effects on healthy tissues of the glioblastoma multiforme (GBM) brain face a challenge with neuroanatomical distortions (tumor, tumor edema, and resection cavities) and limited comparisons can be drawn across studies due to lack of a universally accepted software package. Our aim is to compare current semi-automated segmentation methods and optimize them for reliability in investigating the effects of chemoradiotherapy on GBM patients. METHODS: A publicly available dataset was used based on predefined inclusion and exclusion criteria. VBM pipelines CAT12 and FSL were tested and optimized to reduce the impact of neuroanatomical distortions. T1-weighted images were screened, and post-processed with FSL and CAT12. Gray matter (GM) and white matter (WM), and cerebrospinal fluid (CSF) volumes of whole brain, tumour-containing and non-tumor containing hemispheres, pre- and post-chemoradiotherapy were calculated and analyzed with Wilcoxon signed-rank tests. Agreement and consistency between FSL and CAT12 were assessed using Bland-Altman plots and intraclass correlation coefficients (ICCs). RESULTS: Post-chemoradiotherapy GM volumes were significantly reduced in whole brain with a compensatory significant increase in CSF volumes, while WM volumes had no significant changes. Similar trends were noted in tumor-containing and non-tumor-containing hemispheres. Bland-Altman plots showed good agreement between FSL and CAT12 processed GM and WM volumes of whole brain, tumor-containing, and non-tumor-containing hemispheres. ICC ≥0.70 was observed in GM [0.70 (0.53-0.82)] and WM [0.75 (0.60-0.85)] volumes of non-tumor-containing hemisphere, and WM [0.71 (0.55-0.83)] volumes of whole brain. GM volumes of tumor-containing hemisphere had good agreement but surprisingly, poor consistency [0.50 (0.25-0.68)]. CSF volumes in non-tumor-containing hemisphere had better agreement and consistency [0.55 (0.32-0.71)] than whole brain [0.49 (0.25-0.67)] and tumor-containing hemisphere CSF [0.36 (0.10-0.58)] volumes. Visual inspection revealed both CAT12 and FSL mis-segmented in the presence of neuroanatomical distortion although CAT12 was more susceptible in the presence of a hematoma. CONCLUSIONS: VBM studies of chemoradiotherapy effects on the brain post-tumor resection remain challenging due to neuroanatomical distortions. A reliable alternative is to use non-tumor-containing hemispheres with no anatomical distortion. Should tumor-containing brains be used, FSL is a more suitable choice, especially in the presence of hematoma distortion.

AB036. Targeting glioblastoma de-novo purine metabolism to overcome chemoradiation resistance: an interim result of phase 0/1 clinical trial in newly diagnosed and recurrent glioblastoma.

BACKGROUND: Glioblastoma cells preferentially use de-novo purine synthesis pathway, whereas normal brain prefers salvage pathway. Mycophenolate mofetil (MMF), a commonly used oral immunosuppressant that inhibits inosine-5'-monophosphate dehydrogenase (IMPDH), a key enzyme in the de-novo purine pathway. Pre-clinical suggested MMF can improve radiation and temozolomide efficacy in glioblastoma which led to this phase 0/1 trial (NCT04477200) to assess MMF's tolerability with chemoradiation in glioblastoma, mycophenolic acid accumulation, and purine synthesis inhibition in tumor. METHODS: In the phase 0 study, eight recurrent glioblastoma patients received MMF at doses ranging 500-2,000 mg BID for 1-week before surgery. The tissues were analyzed using mass spectrometry for drug accumulation and purine synthesis inhibition. In the phase 1 study, adult patients were given MMF starting at 1,000 mg orally (PO) twice daily (BID), with the possible dose ranging 500-2,000 PO BID. Nineteen recurrent glioblastoma patients (target N=30) received MMF 1-week prior to and concurrently with re-irradiation (40.5 Gy). Thirty newly diagnosed glioblastoma patients received MMF 1-week prior to and concurrently with chemoradiation, followed by MMF 1-day before and during 5 days of each adjuvant temozolomide cycle. RESULTS: Both enhancing and non-enhancing tumors from phase 0 subjects yielded >1 µM active drug metabolite, and the guanosine triphosphate: inosine monophosphate ratio was decreased by 75% in enhancing tumors in MMF-treated patients compared to untreated controls (P=0.009), indicating effective target engagement and inhibition of purine synthesis. In the phase 1 study, no dose-limiting toxicities (DLTs) were observed at the interim analysis at MMF 1,000-1,500 mg BID combined with chemoradiation. At 2,000 mg BID, there was no DLT combined with temozolomide alone, however, there were four DLTs noted (hemiparesis, cognitive disturbance, fatigue, thrombocytopenia) when combined with radiotherapy and temozolomide together, though all were reversible. Interim median overall survival in recurrent phase 1 is 15.6 months, and not reached yet in newly diagnosed phase 1. CONCLUSIONS: MMF with chemoradiation has been reasonably well tolerated and showed promising evidence of brain tumor target engagement and drug accumulation. This study led to a recommended phase 2 dose of MMF 1,500 mg BID and will provide a preliminary efficacy estimate for a randomized phase 2/3 trial through the Alliance for Clinical Trials in Oncology.