Genetic analysis of oligo-recurrence breast cancer: correlation with clinical outcomes.

BACKGROUND: We aimed to identify the relationship between the genomic characteristics and clinical outcomes of oligo-metastatic breast cancer. METHODS: Oligo-metastatic breast cancer diagnosed by pathology from January 2001 and August 2019 were reviewed and we matched the poly-metastatic patients based on the clinicopathological features of patients included. Clinicopathological values and data of genomic alterations were collected. Oligo-recurrence (oligo-R) was defined as a situation where disease progression occurred in less than 5 anatomical sites and other anatomic areas still suppressed by the ongoing therapy. RESULTS: A total of 26 breast cancer patients were enrolled in our study, including 14 patients with strict oligo-metastatic disease (oligo-R > 6 months) and 12 with simultaneous poly-metastatic disease. PIK3CA, TP53 and ERBB2 were the most common shared alterations identified in patients included. Based on the median time of oligo-R, we divided the patients with oligo-metastasis into longer oligo-R group (oligo-R > 31.04 months) and shorter oligo-R group (oligo-R ≤ 31.04 months). The analysis of PIK3CA mutation sites showed that H1047R mutation was closely associated with oligo-metastasis, rather than poly-metastasis. H1047R mutation also predicted a better prognosis (oligo-R > 31.04 months) in oligo-metastatic breast cancer. In addition, HER2 positive was more likely to be related to a good outcome in patients with oligo-metastasis. CONCLUSIONS: Through the genetic analysis of samples from oligo-metastasis, we found the prognostic values of PIK3CA H1047R and HER2 in oligo- and poly-metastasis. We improved the stratification of prognosis and provided new insights for biological behaviors of oligo-metastatic breast cancer.

Post-recurrence survival analysis in patients with oligo-recurrence after curative esophagectomy.

BACKGROUND: Recurrent esophageal cancer is associated with dismal prognosis. There is no consensus about the role of surgical treatments in patients with limited recurrences. This study aimed to evaluate the role of surgical resection in patients with resectable recurrences after curative esophagectomy and to identify their prognostic factors. METHODS: We retrospectively reviewed patients with recurrent esophageal cancer after curative esophagectomy between 2004 and 2017 and included those with oligo-recurrence that was amenable for surgical intent. The prognostic factors of overall survival (OS) and post-recurrence survival (PRS), as well as the survival impact of surgical resection, were analyzed. RESULTS: Among 654 patients after curative esophagectomies reviewed, 284 (43.4%) had disease recurrences. The recurrences were found resectable in 63 (9.6%) patients, and 30 (4.6%) patients received surgery. The significant prognostic factors of PRS with poor outcome included mediastinum lymph node (LN) recurrence and pathologic T3 stage. In patients with and without surgical resection for recurrence cancer, the 3-year OS rates were 65.6 and 47.6% (p = 0.108), while the 3-year PRS rates were 42.9 and 23.5% (p = 0.100). In the subgroup analysis, surgery for resectable recurrence, compared with non-surgery, could achieve better PRS for patients without any comorbidities (hazard ratio 0.36, 95% CI: 0.14 to 0.94, p = 0.038). CONCLUSIONS: Mediastinum LN recurrence or pathologic T3 was associated with worse OS and PRS in patients with oligo-recurrences after curative esophagectomies. No definite survival benefit was noted in patients undergoing surgery for resectable recurrence, except in those without comorbidities.

Role of high-dose salvage radiotherapy for oligometastases of the localised abdominal/pelvic lymph nodes: a retrospective study.

BACKGROUND: Abdominal/pelvic lymph node (LN) oligometastasis, a pattern of treatment failure, is observed occasionally, and radiotherapy may work as salvage therapy. The optimal prescription dose, however, is yet to be determined. This study assessed the efficacy of high-dose radiotherapy. METHODS: The medical records of 113 patients at 4 institutes were retrospectively analysed who had 1 to 5 abdominal/pelvic LN oligometastases and were treated with definitive radiotherapy between 2008 and 2018. The exclusion criteria included non-epithelial tumours, uncontrolled primary lesions, palliative intent, and re-irradiation. The prescription dose was evaluated by using the equivalent dose in 2 Gy fractions (EQD2). Patients receiving EQD2 ≥ 60 Gy were placed into the high-dose group, and the remaining others the low-dose group. Kaplan-Meier analyses were performed to evaluate overall survival (OS), local control (LC), and progression-free survival (PFS). Univariate log-rank and multivariate Cox proportional hazards model analyses were performed to explore predictive factors. Adverse events were compared between the high-dose and low-dose groups. RESULTS: The primary tumour sites included the colorectum (n = 28), uterine cervix (n = 27), endometrium (n = 15), and ovaries (n = 10). The rate of 2-year OS was 63.1%, that of LC 59.7%, and that of PFS 19.4%. On multivariate analyses, OS were significantly associated with solitary oligometastasis (hazard ratio [HR]: 0.48, p = 0.02), LC with high-dose radiotherapy (HR: 0.93, p < 0.001), and PFS with long disease-free interval (HR: 0.59, p = 0.01). Whereas high-dose radiotherapy did not significantly improve 2-year OS in the entire cohort (74.8% in the high-dose vs. 52.7% in the low-dose; p = 0.08), it did in the subgroup of solitary oligometastasis (88.8% in the high-dose vs. 56.3% in the low-dose; p = 0.009). As for Late grade ≥ 3 adverse event, ileus was observed in 7 patients (6%) and gastrointestinal bleeding in 4 (4%). No significant association between the irradiation dose and adverse event incidence was found. CONCLUSIONS: As salvage therapy, high-dose radiotherapy was recommendable for oligometastasis in the abdominal/pelvic LNs. For solitary oligometastasis, LC and OS were significantly better in the high-dose group.

Analyses of the local control of pulmonary Oligometastases after stereotactic body radiotherapy and the impact of local control on survival.

BACKGROUND: Successful local therapy for oligometastases may lead to longer survival. The purpose of this multicentre retrospective study was to investigate factors affecting the local control (LC) of pulmonary oligometastases treated by stereotactic body radiotherapy (SBRT) and to investigate the impact of LC on survival. METHODS: The inclusion criteria included 1 to 5 metastases, the primary lesion and other extrathoracic metastases were controlled before SBRT, and the biological effective dose (BED10) of the SBRT was 75 Gy or more. The Cox proportional hazards model was used for analyses. RESULTS: Data of 1378 patients with 1547 tumours from 68 institutions were analysed. The median follow-up period was 24.2 months. The one-year, 3-year and 5-year LC rates were 92.1, 81.3 and 78.6%, respectively, and the 1-year, 3-year and 5-year overall survival rates were 90.1, 60.3 and 45.5%, respectively. Multivariate analysis for LC showed that increased maximum tumour diameter (p = 0.011), type A dose calculation algorithm (p = 0.005), shorter overall treatment time of SBRT (p = 0.035) and colorectal primary origin (p < 0.001 excluding oesophagus origin) were significantly associated with a lower LC rate. In the survival analysis, local failure (p < 0.001), worse performance status (1 vs. 0, p = 0.013; 2-3 vs. 0, p < 0.001), oesophageal primary origin (vs. colorectal origin, p = 0.038), squamous cell carcinoma (vs. adenocarcinoma, p = 0.006) and increased maximum tumour diameter (p < 0.001) showed significant relationships with shorter survival. CONCLUSIONS: Several factors of oligometastases and SBRT affected LC. LC of pulmonary oligometastases by SBRT showed a significant survival benefit compared to patients with local failure.

Carbon-ion radiotherapy for lymph node oligo-recurrence: a multi-institutional study by the Japan Carbon-Ion Radiation Oncology Study Group (J-CROS).

BACKGROUND: The efficacy of carbon-ion radiotherapy (C-ion RT) for lymph node (LN) oligo-recurrence has only been evaluated in limited single-center studies. We aimed to investigate the benefit of C-ion RT for LN oligo-recurrence in a large multi-center study. METHODS: Patients who received C-ion RT between December 1996 and December 2015 at 4 participating facilities and who met the following eligibility criteria were included: (i) histological or clinical diagnosis of LN recurrence; (ii) controlled primary lesion; (iii) no recurrence other than LN; (iv) LN recurrence involved in a single lymphatic site; and (v) age ≥ 20 years. RESULTS: A total of 323 patients were enrolled. Median follow-up period was 34 months for surviving patients. The most common dose fractionation of C-ion RT was 48.0 Gy (relative biological effectiveness) in 12 fractions. Forty-seven patients had a history of RT at the recurrent site. The 2-year local control (LC) and overall survival (OS) rates after C-ion RT were 85% and 63%, respectively. Only 1 patient developed grade-3 toxicity. Factors such as LN diameter, histology, and history of previous RT did not correlate with LC. Smaller diameters (< 30 mm) and numbers (≤ 3) of LN metastases as well as longer disease-free intervals post-primary therapy (≥ 16 months) were associated with significantly better OS. CONCLUSIONS: C-ion RT for LN oligo-recurrence appeared to be effective and safe. C-ion RT may provide a survival benefit to patients with LN oligo-recurrence, particularly to those with few LN metastases, smaller LN diameters, and longer disease-free intervals.

The SBRT database initiative of the German Society for Radiation Oncology (DEGRO): patterns of care and outcome analysis of stereotactic body radiotherapy (SBRT) for liver oligometastases in 474 patients with 623 metastases.

BACKGROUND: The intent of this pooled analysis as part of the German society for radiation oncology (DEGRO) stereotactic body radiotherapy (SBRT) initiative was to analyze the patterns of care of SBRT for liver oligometastases and to derive factors influencing treated metastases control and overall survival in a large patient cohort. METHODS: From 17 German and Swiss centers, data on all patients treated for liver oligometastases with SBRT since its introduction in 1997 has been collected and entered into a centralized database. In addition to patient and tumor characteristics, data on immobilization, image guidance and motion management as well as dose prescription and fractionation has been gathered. Besides dose response and survival statistics, time trends of the aforementioned variables have been investigated. RESULTS: In total, 474 patients with 623 liver oligometastases (median 1 lesion/patient; range 1­4) have been collected from 1997 until 2015. Predominant histologies were colorectal cancer (n = 213 pts.; 300 lesions) and breast cancer (n = 57; 81 lesions). All centers employed an SBRT specific setup. Initially, stereotactic coordinates and CT simulation were used for treatment set-up (55%), but eventually were replaced by CBCT guidance (28%) or more recently robotic tracking (17%). High variance in fraction (fx) number (median 1 fx; range 1­13) and dose per fraction (median: 18.5 Gy; range 3­37.5 Gy) was observed, although median BED remained consistently high after an initial learning curve. Median follow-up time was 15 months; median overall survival after SBRT was 24 months. One- and 2-year treated metastases control rate of treated lesions was 77% and 64%; if maximum isocenter biological equivalent dose (BED) was greater than 150 Gy EQD2Gy, it increased to 83% and 70%, respectively. Besides radiation dose colorectal and breast histology and motion management methods were associated with improved treated metastases control. CONCLUSION: After an initial learning curve with regards to total cumulative doses, consistently high biologically effective doses have been employed translating into high local tumor control at 1 and 2 years. The true impact of histology and motion management method on treated metastases control deserve deeper analysis. Overall survival is mainly influenced by histology and metastatic tumor burden.

Surgical treatment in non-small cell lung cancer with pulmonary oligometastasis.

BACKGROUND: Previous studies have demonstrated survival benefits for local treatment in solitary metastatic non-small cell lung cancer (NSCLC).This study aimed to investigate the effect of local surgery for NSCLC with pulmonary oligometastasis. METHODS: This study included 21 patients of NSCLC with pulmonary oligometastasis between January 2003 and December 2013, which were divided into two groups, group A (11 cases) for local surgery and group B (10 cases) for systematic chemotherapy, compared the median survival time (MST) and 5-year survival rate between the two groups, and analyzed the impact of the pathological types, the TNM and pN stage of primary tumor, the site, and the mode and number of oligometastatic nodule on group A. RESULTS: The MST of group A and B were 37 and 11.6 months respectively, 5-year survival rates were 18.2 and 9.1% respectively (p < 0.05). Patients with single nodule, oligo-recurrence, primary tumor of pN0, TNM stage I or II obtained higher survival rate than those with multiple nodules, sync-oligometastases, pN1-2, stage III or IV in group A (p < 0.05). There was no significant survival time difference among pathological types of primary tumor and oligometastatic site (p > 0.05). CONCLUSION: Local surgery significantly prolonged the overall survival time and 5-year survival rate of primary NSCLC with pulmonary oligometastasis.

Oligo-recurrence predicts favorable prognosis of brain-only oligometastases in patients with non-small cell lung cancer treated with stereotactic radiosurgery or stereotactic radiotherapy: a multi-institutional study of 61 subjects.

BACKGROUND: To investigate the prognostic value of oligo-recurrence in patients with brain-only oligometastases of non-small cell lung cancer (NSCLC) treated with stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT). METHODS: Patients treated with SRS or SRT for brain-only NSCLC oligometastases in 6 high-volume institutions in Japan between 1996 and 2008 were reviewed. Eligible patients met 1), 2), and 4) or 1), 3), and 4) of the following: 1) NSCLC with 1 to 4 brain metastases on magnetic resonance imaging (MRI) treated with SRS or SRT; 2) control of the primary lesions (thorax) at the time of SRS or SRT for brain metastases (patients meeting this criterion formed the oligo-recurrence group); 3) with SRS or SRT for brain metastases, concomitant treatment for active primary lesions (thorax) with curative surgery or curative stereotactic body radiotherapy (SBRT), or curative chemoradiotherapy (sync-oligometastases group); and 4) Karnofsky performance status (KPS) ≥70. RESULTS: The median overall survival (OS) of all 61 patients was 26 months (95 % CI: 17.5-34.5 months). The 2-year and 5-year overall survival rates were 60.7 and 15.7 %, respectively. Stratified by oligostatus, the sync-oligometastases group achieved a median OS of 18 months (95 % CI: 14.8-21.1 months) and a 5-year OS of 0 %, while the oligo-recurrence group achieved a median OS of 41 months (95 % CI: 27.8-54.2 months) and a 5-year OS of 18.6 %. On multivariate analysis, oligo-recurrence was the only significant independent factor related to a favorable prognosis (hazard ratio: 0.253 (95 % CI: 0.082-0.043) (p = 0.025). CONCLUSIONS: The presence of oligo-recurrence can predict a favorable prognosis of brain-only oligometastases in patients with NSCLC treated with SRS or SRT.

Lung stereotactic radiotherapy for oligometastases: comparison of oligo-recurrence and sync-oligometastases.

BACKGROUND: Oligometastases can be divided into sync-oligometastases and oligo-recurrence. The difference is whether the primary site is uncontrolled or controlled. The goal of this multicenter study was to evaluate treatment outcomes and factors affecting survival after stereotactic body radiotherapy for pulmonary oligometastases. METHODS: The information after stereotactic body radiotherapy from January 2004 to April 2014 was retrospectively collected. Ninety-six patients (65 males, 31 females) were enrolled. Ten cases (10%) were sync-oligometastases, 79 cases (82%) were oligo-recurrences and 7 (7%) were unclassified oligometastases with <6 months of disease-free interval. The median disease-free interval between initial therapy and stereotactic body radiotherapy was 24 months. The median calculated biological effective dose was 105.6 Gy. RESULTS: The median follow-up period was 32 months for survivors. The 3-year overall survival and relapse-free survival rates were 53% and 32%, respectively. No Grade 5 toxicity occurred. The median overall survival was 23.9 months for sync-oligometastases and 66.6 months for oligo-recurrence (P = 0.0029). On multivariate analysis, sync-oligometastases and multiple oligometastatic tumors were significant unfavorable factors for both overall survival and relapse-free survival. CONCLUSIONS: In stereotactic body radiotherapy for oligometastatic lung tumors, the state of oligo-recurrence has the potential of a significant prognostic factor for survival.

Optimal Treatment Strategy for Oligo-Recurrence Lung Cancer Patients with Driver Mutations.

BACKGROUND: The efficacy of local therapies for lung cancer patients with postoperative oligo-recurrence has been reported. However, whether local therapies should be chosen over molecular targeted therapies for oligo-recurrence patients with driver mutations remains controversial. Therefore, we aimed to investigate the optimal initial treatment strategy for oligo-recurrence in lung cancer patients with driver mutations. METHODS: Among 2152 patients with lung adenocarcinoma who underwent surgical resection at our institute between 2008 and 2020, 66 patients with driver mutations who experienced cancer oligo-recurrence after surgery and were treated with local or molecularly targeted therapy as an initial therapy after recurrence were evaluated. Oligo-recurrence was characterized by the presence of 1 to 3 recurrent lesions. These patients were investigated, focusing on their post-recurrence therapies and prognoses. RESULTS: The median follow-up period was 71 months. Local and molecular targeted therapies were administered to 41 and 25 patients, respectively. The number of recurrence lesions tended to be lower in the initial local therapy group than in the molecular targeted therapy group. In the initial local therapy group, 23 patients (56%) subsequently received molecular targeted therapies. The time from recurrence to the initiation of molecular targeted therapy was significantly longer in the local therapy group than in the molecular targeted therapy group (p < 0.001). There was no significant difference in post-recurrence overall survival (hazard ratio, 1.429; 95% confidence interval, 0.701-2.912; log-rank, p = 0.324) and post-recurrence progression-free survival (hazard ratio, 0.799; 95% confidence interval, 0.459-1.390; log-rank, p = 0.426) in the initial local ablative therapy group compared with the initial molecular targeted therapy group. CONCLUSIONS: Local therapies as a first-line treatment did not show statistically significant differences in post-recurrence survival or progression-free survival compared with molecular targeted therapies. However, local therapies as an initial treatment should be considered preferably, as they can cure the recurrence and can delay the start of administration of molecular targeted therapies.

Brain Metastasis of Non-small Cell Lung Cancer After Disease-Free Survival of 5 years: Case Series and Comprehensive Literature Review.

BACKGROUND: In the treatment of nonsmall cell lung cancer (NSCLC), a disease-free survival of 5 years is a criterion for cure. This study aimed to evaluate the characteristics and outcomes of patients with brain metastases of NSCLC after a disease-free survival of 5 years (late recurrent brain metastasis [LRBM]). METHODS: We reviewed 1281 consecutive patients with brain metastasis of lung cancer at a single institute between November 2014 and December 2022. Relevant articles were retrieved from PubMed. Only peer-reviewed journals published in English were included. RESULTS: Six patients (0.47%) showed LRBM. Three were male. The median age at lung cancer diagnosis was 45 years. The histological diagnosis of all patients was adenocarcinoma. Driver gene mutations were observed in five patients. The median latency period from lung cancer treatment to the development of brain metastasis was 13 years. All patients had no metastasis to any other organs and underwent craniotomies. The median follow-up duration after craniotomy was 3.5 years. No local intracranial recurrences were observed. Three patients had distant intracranial recurrences at 7, 2, and 0.6 years after craniotomy. Five patients survived for 8, 4, 3, 2, and 0.3 years after craniotomy. One patient experienced re-recurrence in the lung 4 years after craniotomy and died 3.7 years later. In our systematic review, only six studies described LRBM of NSCLC. CONCLUSIONS: LRBM is rare in patients with NSCLC. In our institution, many of these patients harbored driver gene mutations, and achieved long-term survival with aggressive local therapy. Multicenter analysis is mandatory.

Predictive Value of the Prostate-specific Antigen Doubling Time for the Effectiveness of Metastasis-directed Radiotherapy in Patients With Oligometastases After Radical Treatment for Non-metastatic Prostate Cancer.

Background/Aim: Data on metastasis-directed radiotherapy (MDRT) are limited, particularly regarding its association with the prostate-specific antigen (PSA) doubling time (PSADT). The present study evaluated the oncological outcomes of MDRT on the basis of the PSADT in oligo-recurrent prostate cancer patients. Patients and Methods: We retrospectively reviewed clinical data of 35 MDRTs for 29 patients at the Kitasato University Hospital, targeting oligometastatic prostate cancer developed after radical treatment for non-metastatic prostate cancer. Thirty-five MDRTs were classified into the PSADT >3 months (n=25) or PSADT ≤3 months group (n=10). Statistical analyses were performed to compare associations between the two PSADT groups and oncological outcomes such as progression-free survival (PFS) and PSA response after MDRT. Results: There were no significant differences between the two groups in terms of the clinicopathological features. Kaplan-Meier analysis showed that PFS was significantly better in the PSADT >3 months group than in the PSADT ≤3 months group [median: 13.3 versus (vs.) 2.6 months, p=0.046]. Regarding castration sensitivity, the predictive role of PSADT >3 months was maintained in 21 patients who received MDRT without prior salvage hormone therapy (median PFS: 12.7 vs. 2.6 months, p=0.024). In the castration-resistant setting (n=14), the frequency of a decrease in serum PSA levels after MDRT by 90% was 54.5% (median PFS: 23.1 months). Conclusion: MDRT can provide benefit especially for patients with PSADT ≥3 months who had oligo-recurrence after the radical treatment for non-metastatic prostate cancer.

Oligometastasis of Gastric Cancer: A Review.

The concept of oligometastasis is not yet fully established in the field of gastric cancer. However, metastatic lesions that are localized, technically resectable at diagnosis, present a certain response to preoperative chemotherapy, and present favorable survival outcomes with local treatments, sometimes in combination with chemotherapy, are recognized as oligometastasis in the field of gastric cancer. Oligometastasis is noted in European Society for Medical Oncology guidelines and Japanese gastric cancer treatment guidelines, and local treatment is mentioned as one of the pivotal treatment options for oligometastasis. Solitary liver metastasis or a small number of liver metastases; retroperitoneal lymph node metastasis, especially localized para-aortic lymph node metastasis; localized peritoneal dissemination; and Krukenberg tumor are representative types of oligometastasis in gastric cancer. The AIO-FLOT3 trial prospectively evaluated the efficacy of multimodal treatments for gastric cancer with oligometastasis, including surgical resection of primary and metastatic lesions combined with chemotherapy, confirming favorable survival outcomes. Two phase 3 studies are ongoing to investigate the efficacy of surgical resection combined with perioperative chemotherapy compared with palliative chemotherapy. Thus far, the evidence suggests that multimodal treatment for oligometastasis of gastric cancer is promising.

Oligometastases of Esophageal Squamous Cell Carcinoma: A Review.

Patients with oligometastases show distant relapse in only a limited number of regions. Local therapy such as surgical resection, radiotherapy, chemoradiotherapy, and radiofrequency ablation for the relapsed sites may thus improve patient survival. Oligometastases are divided into oligo-recurrence and sync-oligometastases. Oligo-recurrence indicates a primary lesion that is controlled, and sync-oligometastases indicate a primary lesion that is not controlled. The management of oligo-recurrence and sync-oligometastases in esophageal squamous cell carcinoma has not been clearly established, and treatment outcomes remain equivocal. We reviewed 14 articles, including three phase II trials, that were limited to squamous cell carcinoma. Multimodal treatment combining surgical resection and chemoradiotherapy for oligo-recurrence of esophageal squamous cell carcinoma appears to be a promising treatment. With the development of more effective chemotherapy and regimens that combine immune checkpoint inhibitors, it will become more likely that sync-oligometastases that were unresectable at the initial diagnosis can be brought to conversion surgery. Currently, a randomized, controlled phase III trial is being conducted in Japan to compare a strategy for performing definitive chemoradiotherapy and, if necessary, salvage surgery with a strategy for conversion surgery in patients who can be resected by induction chemotherapy.

Effect of local treatment in patients with oligo-recurrence after surgery of distal bile duct cancer: A bi-institutional study.

BACKGROUND: Distal extrahepatic bile duct (EHBD) cancer is highly recurrent. More than 50% of patients suffer from disease relapse after curative resection. Some patients present with oligo-recurrence which could be a single loco-regional mass or lesions limited to a single solid organ. The aim of this study was to examine the effect of local control (surgical resection or radiofrequency ablation) on survival outcomes in patients with oligo-recurrent distal EHBD cancer. METHODS: Data of 1219 patients who underwent surgery for distal EHBD cancer from 2000 to 2018 were retrospectively reviewed. Clinicopathological characteristics and survival outcomes of patients with recurrence were investigated. Post-recurrence survival (PRS) was analyzed according to modalities of re-treatment (local treatment or systemic therapy alone). RESULTS: Among 654 patients with recurrence, 90 patients who had oligo-recurrence showed better recurrence-free and overall survival than patients with non-oligo-recurrent disease. Lymph node ratio and perineural invasion at initial pathology, timing of recurrence, and platelet-to-lymphocyte ratio at recurrence were independent risk factors for PRS in the oligo-recurrent group. Patients with local treatment for oligo-recurrence had better 3- and 5-year PRS than those with systemic treatment alone (38.3% vs. 14.1%, p = 0.04; 28.3% vs. 7.1%, p = 0.04, respectively). Recurrence within 24 months after initial surgery was the only significant factor for PRS in the local treatment group. CONCLUSION: In patients with oligo-recurrence after resection of distal EHBD cancer, post-recurrence local treatment could improve survival outcomes, particularly for those with recurrence more than 2 years after initial resection.

Examination of the effectiveness of local therapy for oligo-recurrence of EGFR-mutated NSCLC.

BACKGROUND: The effectiveness of local therapy has been reported in patients with oligo-recurrence of non-small cell lung cancer (NSCLC), a metachronous recurrence with a limited number of recurrences, which can be treated with local therapy. Conversely, remarkable progress has been made in systemic therapy for NSCLC with the advent of molecular targeted therapy. In particular, epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are very effective in the treatment of EGFR-mutated NSCLC. There is currently no consensus on treatment for oligo-recurrence of EGFR-mutated NSCLC. METHODS: From 2004 to 2014, 811 patients underwent complete resection for NSCLC at Kitasato University Hospital and, of these, 244 patients developed recurrence. Oligo-recurrence was defined as the presence of two or less recurrent lesions, and 34 patients presented with EGFR-mutated oligo-recurrence. RESULTS: We retrospectively examined and compared the effects of EGFR-TKIs with those of radical local therapy in patients with oligo-recurrent EGFR-mutated NSCLC. The five-year post-recurrence survival (PRS) rates of patients with EGFR-mutated oligo-recurrence who received radical local therapy (n = 23) and those who did not (n = 11) were 59.4 and 45.5%, respectively (p = 0.777). Multivariate analysis revealed no favorable prognostic factors associated with prolonged PRS, and radical local therapies did not improve PRS in patients with oligo-recurrence (p = 0.551). CONCLUSION: Radical local therapy did not affect PRS in patients with oligo-recurrent EGFR-mutated NSCLC. Even in cases of oligo-recurrence, the administration of local therapy in patients with EGFR-mutated NSCLC might be carefully considered.

Pattern of failure and clinical value of local therapy for oligo-recurrence in locally advanced non-small cell lung cancer after definitive chemoradiation: Impact of driver mutation status.

INTRODUCTION: Considerable differences of treatment response and pattern of failure may exist between definitive chemoradiation (CRT) treated locally advanced non-small cell lung cancer (LA-NSCLC) patients. The clinical value of additional tyrosine kinase inhibitors (TKIs) before disease recurrence and salvage local therapy after initial recurrent disease remain controversial. METHODS AND MATERIALS: Consecutive LA-NSCLC patients receiving definitive CRT and having definite results about driver mutations (EGFR, ALK and ROS1) were retrospectively reviewed. Initial recurrent disease was classified as in-field recurrence, out-of-field recurrence and distant metastasis. Recurrent disease occurred only in the brain or limited to ≤3 extra-cranial organs and ≤5 extra-cranial lesions, was defined as oligo-recurrence. Progression free survival and overall survival (OS) were calculated from diagnosis to disease progression or death, and to death, respectively. OS2 was measured from initial disease recurrence to death among patients who had recurrent disease. RESULTS: Of the 153 enrolled patients, 39 had driver mutations and 13 received additional TKI therapy besides definitive CRT. Patients harboring driver mutations but without additional TKI therapy had a similar PFS and significantly longer OS (p = 0.032) than those without driver mutations. Additional TKI therapy prolonged PFS (p = 0.021) but not OS among patients with driver mutations. No significant difference of pattern of failure was observed between patient subgroups stratified by the status of driver mutations and the usage of additional TKI therapy. Furthermore, 57 of the 95 patients with initial recurrent disease developed oligo-recurrence and salvage local therapy significantly improved OS2 (p = 0.01) among patients with oligo-recurrence disease. CONCLUSION: LA-NSCLC patients receiving definitive CRT generally had similar PFS and pattern of treatment failure, regardless of driver mutation status. Additional TKI therapy besides definitive CRT could prolong PFS but not OS. The majority of recurrent disease after definitive CRT belongs to oligo-recurrence and salvage local therapy may provide survival benefit.

Optimizing Treatment Strategy for Oligometastases/Oligo-Recurrence of Colorectal Cancer.

Colorectal cancer (CRC) is the third most common cancer, and nearly half of CRC patients experience metastases. Oligometastatic CRC represents a distinct clinical state characterized by limited metastatic involvement, demonstrating a less aggressive nature and potentially improved survival with multidisciplinary treatment. However, the varied clinical scenarios giving rise to oligometastases necessitate a precise definition, considering primary tumor status and oncological factors, to optimize treatment strategies. This review delineates the concepts of oligometastatic CRC, encompassing oligo-recurrence, where the primary tumor is under control, resulting in a more favorable prognosis. A comprehensive examination of multidisciplinary treatment with local treatments and systemic therapy is provided. The overarching objective in managing oligometastatic CRC is the complete eradication of metastases, offering prospects of a cure. Essential to this management approach are local treatments, with surgical resection serving as the standard of care. Percutaneous ablation and stereotactic body radiotherapy present less invasive alternatives for lesions unsuitable for surgery, demonstrating efficacy in select cases. Perioperative systemic therapy, aiming to control micrometastatic disease and enhance local treatment effectiveness, has shown improvements in progression-free survival through clinical trials. However, the extension of overall survival remains variable. The review emphasizes the need for further prospective trials to establish a cohesive definition and an optimized treatment strategy for oligometastatic CRC.

The Diagnosis and Treatment Approach for Oligo-Recurrent and Oligo-Progressive Renal Cell Carcinoma.

One-third of renal cell carcinomas (RCCs) without metastases develop metastatic disease after extirpative surgery for the primary tumors. The majority of metastatic RCC cases, along with treated primary lesions, involve limited lesions termed "oligo-recurrent" disease. The role of metastasis-directed therapy (MDT), including stereotactic body radiation therapy (SBRT) and metastasectomy, in the treatment of oligo-recurrent RCC has evolved. Although the surgical resection of all lesions alone can have a curative intent, SBRT is a valuable treatment option, especially for patients concurrently receiving systemic therapy. Contemporary immune checkpoint inhibitor (ICI) combination therapies remain central to the management of metastatic RCC. However, one objective of MDT is to delay the initiation of systemic therapies, thereby sparing patients from potentially unnecessary burdens. Undertaking MDT for cases showing progression under systemic therapies, known as "oligo-progression", can be complex in considering the treatment approach. Its efficacy may be diminished compared to patients with stable disease. SBRT combined with ICI can be a promising treatment for these cases because radiation therapy has been shown to affect the tumor microenvironment and areas beyond the irradiated sites. This may enhance the efficacy of ICIs, although their efficacy has only been demonstrated in clinical trials.

Efficacy and Safety of Radioactive 125I Seed Implantation for Patients with Oligo-Recurrence Soft Tissue Sarcomas.

PURPOSE: To evaluate the efficacy and safety of computed tomography-guided radioactive iodine-125 (125I) seed implantation for oligo-recurrence soft tissue sarcomas following surgical resection. MATERIALS AND METHODS: Patients with oligo-recurrence soft tissue sarcomas after curative surgical resection between June 2013 and December 2020 were included. The primary outcome measure was objective response rate according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1). The secondary outcomes included progression-free survival, overall survival, and safety profiles. RESULTS: Twenty-nine patients receiving computed tomography-guided 125I seed implantation were included in the study. The objective response rates at 2-, 6- and 12-month follow-up were 48.3%, 65.5% and 40.9%, respectively. The median progression-free survival was 11.3 months. The median overall survival was 25.1 months, with a 1- and 2-year overall survival rate of 81.5% and 50.0%, respectively. No severe treatment-related adverse effects occured. CONCLUSION: 125I seed implantation has the potential to be an effective and safe treatment for oligo-recurrence soft tissue sarcomas after surgical resection.