Prognostic value of the micronucleus assay for clinical endpoints in neoadjuvant radiochemotherapy for rectal cancer.

BACKGROUND: The question whether lymphocyte radiosensitivity is representative of patients' response to radiotherapy (RT) remains unsolved. We analyzed lymphocyte cytogenetic damage in patients who were homogeneously treated with preoperative radiochemotherapy (RCT) for rectal cancer within clinical trials. We tested for interindividual variation and consistent radiosensitivity after in-vivo and in-vitro irradiation, analyzed the effect of patients' and RCT characteristics on cytogenetic damage, and tested for correlations with patients' outcome in terms of tumor response, survival and treatment-related toxicity. METHODS: The cytokinesis-block micronucleus cytome (CBMNcyt) assay was performed on the peripheral blood lymphocytes (PBLCs) of 134 patients obtained before, during, at the end of RCT, and during the 2-year follow-up. A subset of PBLCs obtained before RCT was irradiated in-vitro with 3 Gy. RCT included 50.4 Gy of pelvic RT with 5-fluorouracil (5-FU) alone (n = 78) or 5-FU plus oxaliplatin (n = 56). The analyzed variables included patients' age, gender, RT characteristics (planning target volume size [PTV size], RT technique), and chemotherapy characteristics (5-FU plasma levels, addition of oxaliplatin). Outcome was analyzed as tumor regression, patient survival, and acute and late toxicity. RESULTS: Cytogenetic damage increased significantly with the radiation dose and varied substantially between individuals. Women were more sensitive than men; no significant age-dependent differences were observed. There was a significant correlation between the cytogenetic damage after in-vitro irradiation and in-vivo RCT. We found a significant effect of the PTV size on the yields of cytogenetic damage after RCT, while the RT technique had no effect. Neither the addition of oxaliplatin nor the 5-FU levels influenced cytogenetic damage. We found no correlation between patient outcome and the cytogenetic damage. CONCLUSIONS: We found consistent cytogenetic damage in lymphocytes after in-vivo RCT and in-vitro irradiation. Gender was confirmed as a well-known, and the PTV size was identified as a less well-known influencing variable on lymphocyte cytogenetic damage after partial-body irradiation. A consistent level of cytogenetic damage after in-vivo and in-vitro irradiation may indicate the importance of genetic factors for individual radiosensitivity. However, we found no evidence that in-vivo or in-vitro irradiation-induced cytogenetic damage is an adequate biomarker for the response to RCT in rectal cancer patients.

MRI versus 68Ga-PSMA PET/CT for gross tumour volume delineation in radiation treatment planning of primary prostate cancer.

PURPOSE: Multiparametric magnetic resonance imaging (mpMRI) is widely used in radiation treatment planning of primary prostate cancer (PCA). Focal dose escalation to the dominant intraprostatic lesions (DIPL) may lead to improved PCA control. Prostate-specific membrane antigen (PSMA) is overexpressed in most PCAs. (68)Ga-labelled PSMA inhibitors have demonstrated promising results in detection of PCA with PET/CT. The aim of this study was to compare (68)Ga-PSMA PET/CT with MRI for gross tumour volume (GTV) definition in primary PCA. METHODS: This retrospective study included 22 patients with primary PCA analysed after (68)Ga-PSMA PET/CT and mpMRI. GTVs were delineated on MR images by two radiologists (GTV-MRIrad) and two radiation oncologists separately. Both volumes were merged leading to GTV-MRIint. GTVs based on PET/CT were delineated by two nuclear medicine physicians in consensus (GTV-PET). Laterality (left, right, and left and right prostate lobes) on mpMRI, PET/CT and pathological analysis after biopsy were assessed. RESULTS: Mean GTV-MRIrad, GTV-MRIint and GTV-PET were 5.92, 3.83 and 11.41 cm(3), respectively. GTV-PET was significant larger then GTV-MRIint (p = 0.003). The MRI GTVs GTV-MRIrad and GTV-MRIint showed, respectively, 40 % and 57 % overlap with GTV-PET. GTV-MRIrad and GTV-MRIint included the SUVmax of GTV-PET in 12 and 11 patients (54.6 % and 50 %), respectively. In nine patients (47 %), laterality on mpMRI, PET/CT and histopathology after biopsy was similar. CONCLUSION: Ga-PSMA PET/CT and mpMRI provided concordant results for delineation of the DIPL in 47 % of patients (40 % - 54 % of lesions). GTV-PET was significantly larger than GTV-MRIint. (68)Ga-PSMA PET/CT may have a role in radiation treatment planning for focal radiation to the DIPL. Exact correlation of PET and MRI images with histopathology is needed.

Reduced toxicity in the treatment of locally advanced rectal cancer: a comparison of volumetric modulated arc therapy and 3D conformal radiotherapy.

BACKGROUND: Excellent dosimetric characteristics were demonstrated for volumetric modulated arc therapy (VMAT) in preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). In a single-center retrospective analysis, we tested whether these advantages may translate into significant clinical benefits. We compared VMAT to conventional 3D conformal radiotherapy (3DCRT) in patients, homogeneously treated according to the control arm of the CAO/ARO/AIO-04 trial. METHODS: CRT consisted of pelvic irradiation with 50.4/1.8Gy by VMAT (n = 81) or 3DCRT (n = 107) and two cycles of 5-fluorouracil. Standardized total mesorectal excision surgery was performed within 4-6 weeks. The tumor regression grading (TRG) was assessed by the Dworak score. Acute and late toxicity were evaluated via the Common Terminology Criteria for Adverse Events and the Late effects of normal tissues scale, respectively. Side effects greater than or equal to grade 3 were considered high-grade. RESULTS: Median follow-up was 18.3 months in the VMAT group and 61.5 months in the 3DCRT group with no differences in TRG between them (p = 0.1727). VMAT treatment substantially reduced high-grade acute and late toxicity, with 5 % versus 20 % (p = 0.0081) and 6 % vs. 22 % (p = 0.0039), respectively. With regard to specific organs, differences were found in skin reaction (p = 0.019) and proctitis (p = 0.0153). CONCLUSIONS: VMAT treatment in preoperative CRT for LARC showed the potential to substantially reduce high-grade acute and late toxicity. Importantly, we could demonstrate that VMAT irradiation did not impair short-term oncological results. We conclude, that the reduced toxicity after VMAT irradiation may pave the way for more efficient systemic therapies, and hopefully improved patient survival in the multimodal treatment of LARC.

Volumetric intensity-modulated arc therapy vs. 3-dimensional conformal radiotherapy for primary chemoradiotherapy of anal carcinoma: Effects on treatment-related side effects and survival.

BACKGROUND: Primary chemoradiotherapy (CRT) is the standard treatment for locally advanced anal carcinoma. This study compared volumetric intensity-modulated arc therapy (VMAT) to 3-dimensional conformal radiotherapy (3DCRT) in terms of treatment-related side effects and survival. PATIENTS AND METHODS: From 1992-2014, 103 consecutive patients with anal carcinoma UICC stage I-III were treated. Concomitant CRT consisted of whole pelvic irradiation, including the iliac and inguinal lymph nodes, with 50.4 Gy (1.8 Gy per fractions) by VMAT (n = 17) or 3DCRT (n = 86) as well as two cycles of 5-fluorouracil and mitomycin C. Acute organ and hematological toxicity were assessed according to the Common Terminology Criteria (CTC) for Adverse Events version 3.0. Side effects ≥ grade 3 were scored as high-grade toxicity. RESULTS: High-grade acute organ toxicity CTC ≥ 3 (P < 0.05), especially proctitis (P = 0.03), was significantly reduced in VMAT patients. The 2-year locoregional control (LRC) and disease-free survival (DFS) were both 100 % for VMAT patients compared with 80 and 73 % for 3DCRT patients. CONCLUSION: VMAT was shown to be a feasible technique, achieving significantly lower rates of acute organ toxicity and promising results for LRC and DFS. Future investigations will aim at assessing the advantages of VMAT with respect to late toxicity and survival after a prolonged follow-up time.

Acute toxicity of radiochemotherapy in rectal cancer patients: a risk particularly for carriers of the TGFB1 Pro25 variant.

PURPOSE: Transforming growth factor-beta1 is related to adverse events in radiochemotherapy. We investigated TGFB1 genetic variability in relation to quality of life-impairing acute organ toxicity (QAOT) of neoadjuvant radiochemotherapy under clinical trial conditions. METHODS AND MATERIALS: Two independent patient cohorts (n = 88 and n = 75) diagnosed with International Union Against Cancer stage II/III rectal cancer received neoadjuvant radiation doses of 50.4 Gy combined with 5-fluorouracil-based chemotherapy. Toxicity was monitored according to Common Terminology Criteria for Adverse Events. QAOT was defined as a CTCAE grade ≥2 for at least one case of enteritis, proctitis, cystitis, or dermatitis. Nine germline polymorphisms covering the common genetic diversity in the TGFB1 gene were genotyped. RESULTS: In both cohorts, all patients carrying the TGFB1 Pro25 variant experienced QAOT (positive predictive value of 100%, adjusted p = 0.0006). In a multivariate logistic regression model, gender, age, body mass index, type of chemotherapy, or disease state had no significant impact on QAOT. CONCLUSION: The TGFB1 Pro25 variant could be a relevant marker for individual treatment stratification and carriers may benefit from adaptive clinical care or specific radiation techniques.

Irradiation with protons for the individualized treatment of patients with locally advanced rectal cancer: a planning study with clinical implications.

BACKGROUND AND PURPOSE: Ongoing clinical trials aim to improve local control and overall survival rates by intensification of therapy regimen for patients with locally advanced rectal cancer. It is well known that whenever treatment is intensified, risk of therapy-related toxicity rises. An irradiation with protons could possibly present an approach to solve this dilemma by lowering the exposure to the organs-at-risk (OAR) without compromising tumor response. MATERIAL AND METHODS: Twenty five consecutive patients were treated from 04/2009 to 5/2010. For all patients, four different treatment plans including protons, RapidArc, IMRT and 3D-conformal-technique were retrospectively calculated and analyzed according to dosimetric aspects. RESULTS: Detailed DVH-analyses revealed that protons clearly reduced the dose to the OAR and entire normal tissue when compared to other techniques. Furthermore, the conformity index was significantly better and target volumes were covered consistent with the ICRU guidelines. CONCLUSIONS: Planning results suggest that treatment with protons can improve the therapeutic tolerance for the irradiation of rectal cancer, particularly for patients scheduled for an irradiation with an intensified chemotherapy regimen and identified to be at high risk for acute therapy-related toxicity. However, clinical experiences and long-term observation are needed to assess tumor response and related toxicity rates.

Gender-specific acute organ toxicity during intensified preoperative radiochemotherapy for rectal cancer.

Patients with locally advanced rectal cancer (cUICC stages II/III) are typically treated with preoperative 5-fluorouracil-based (5-FU-based) radiochemotherapy (RCT). However, trials are currently being conducted to improve the complete remission rates and the systemic control by combining 5-FU with oxaliplatin. The primary objective was to identify the subgroups of rectal cancer patients who were at risk for high-grade toxicity. All 196 patients who were included in the present study were treated with 50.4 Gy and chemotherapy that included either 5-FU (n = 115) or 5-FU+oxaliplatin (n = 81). The preoperative RCT was followed by a total mesorectal excision and adjuvant chemotherapy. Acute toxicity was monitored weekly and a toxicity grade ≥3 (Common Toxicity Criteria) for a skin reaction, cystitis, proctitis, or enteritis was defined as high-grade acute organ toxicity. After RCT with 5-FU+oxaliplatin, complete tumor remission was achieved in 13.6% of the patients and in 11.3% after RCT with 5-FU alone. Complete irradiation dosages of 50.4 Gy were given to 99% (5-FU) and 95% (5-FU+oxaliplatin) of the patients. Concomitant chemotherapy was fully administered in 95% of the patients treated with 5-FU compared with the 84% of patients treated with 5-FU+oxaliplatin. A significantly higher proportion of acute organ toxicity was found in the patients who were treated with 5-FU+oxaliplatin compared with those who were treated with 5-FU. Additionally, women with a low body mass index were at the highest risk for acute organ toxicity. These results suggest that there are basic clinical parameters, such as gender and body mass index, that may be potential markers for generating individual risk profiles of RCT-induced toxicity.

High-grade acute organ toxicity as positive prognostic factor in adjuvant radiation and chemotherapy for locally advanced head and neck cancer.

PURPOSE: To test for an association between high-grade acute organ toxicity during adjuvant radiation and chemotherapy and treatment outcome in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: Institutional review board approval was obtained for this retrospective study. From September 1994 to October 2008, 294 HNSCC patients were treated with adjuvant radiation and chemotherapy at the authors' department. They received normofractionated (2 Gy per fraction) irradiation to include associated nodal drainage sites, for a cumulative dose of 60-64 Gy. From January 2002 to December 2009, 91 patients received additional concomitant cisplatin-based chemotherapy. Toxicity during treatment was monitored weekly according to the common toxicity criteria (CTC); any CTC toxicity grade 3 or higher, including mucositis, dysphagia, or skin reaction, was considered high-grade acute organ toxicity. The influence of possible prognostic factors on overall survival and locoregional control was studied by means of uni- and multivariate Cox regression. RESULTS: A statistically significant association was found between high-grade acute organ toxicity and both overall survival and locoregional control. Patients with CTC grade 3 or greater acute organ toxicity had a 5-year overall survival and locoregional control rate of 90% and 97%, respectively, as compared with 24% and 74%, respectively, in patients without such toxicity (P < .01). Multivariate analyses revealed that this association was independent from other factors that may influence treatment toxicity, especially concomitant chemotherapy and/or radiation therapy. CONCLUSION: The data suggest that normal tissue and tumor tissue may behave similarly with respect to treatment response, as high-grade acute organ toxicity during radiation and chemotherapy was associated with better outcomes in the patient population; therefore, the hypothesis should be further analyzed on the biomolecular and clinical level and with other tumor entities in prospective clinical trials.

Comparison of the micronucleus and chromosome aberration techniques for the documentation of cytogenetic damage in radiochemotherapy-treated patients with rectal cancer.

PURPOSE: The goal of the interdisciplinary Clinical Research Unit KFO179 (Biological Basis of Individual Tumor Response in Patients with Rectal Cancer) is to develop an individual Response and Toxicity Score for patients with locally advanced rectal cancer treated with neoadjuvant radiochemotherapy. The aim of the present study was to find a reliable and sensitive method with easy scoring criteria and high numbers of cell counts in a short period of time in order to analyze DNA damage in peripheral blood lymphocytes. Thus, the cytokinesis-block micronucleus (CBMN) assay and the chromosome aberration technique (CAT) were tested. MATERIALS AND METHODS: Peripheral blood lymphocytes obtained from 22 patients with rectal cancer before (0 Gy), during (21.6 Gy), and after (50.4 Gy) radiochemotherapy were stimulated in vitro by phytohemagglutinin (PHA); the cultures were then processed for the CBMN assay and the CAT to compare the two methods. RESULTS: A significant increase of chromosomal damage was observed in the course of radiochemotherapy parallel to increasing radiation doses, but independent of the chemotherapy applied. The equivalence of both methods was shown by Westlake's equivalence test. CONCLUSION: The results show that the CBMN assay and the CAT are equivalent. For further investigations, we prefer the CBMN assay, because it is simpler through easy scoring criteria, allows high numbers of cell counts in less time, is reliable, sensitive, and has higher statistical power. In the future, we plan to integrate cytogenetic damage during radiochemotherapy into the planned Response and Toxicity Score within our interdisciplinary Clinical Research Unit.

High-grade acute organ toxicity as a positive prognostic factor in primary radiochemotherapy for anal carcinoma.

PURPOSE: To test for a possible correlation between high-grade acute organ toxicity during primary radiochemotherapy and treatment outcome for patients with anal carcinoma. METHODS AND MATERIALS: From 1991 to 2009, 72 patients with anal carcinoma were treated at our department (10 patients had stage I, 28 patients had stage II, 11 patients had stage IIIA, and 13 patients had stage IIIB cancer [Union Internationale Contre le Cancer criteria]). All patients received normofractionated (1.8 Gy/day, five times/week) whole-pelvis irradiation including iliac and inguinal lymph nodes with a cumulative dose of 50.4 Gy. Concomitant chemotherapy regimen consisted of two cycles of 5-fluorouracil (1,000 mg/m(2)total body surface area (TBSA)/day as continuous intravenous infusion on days 1-4 and 29-32) and mitomycin C (10 mg/m(2)/TBSA, intravenously on days 1 and 29). Toxicity during treatment was monitored weekly, and any incidence of Common Toxicity Criteria (CTC) grade of ≥3 for skin reaction, cystitis, proctitis, or enteritis was assessed as high-grade acute organ toxicity for later analysis. RESULTS: We found significant correlation between high-grade acute organ toxicity and overall survival, locoregional control, and stoma-free survival, which was independent in multivariate analysis from other possible prognostic factors: patients with a CTC acute organ toxicity grade of ≥3 had a 5-year overall survival rate of 97% compared to 30% in patients without (p < 0.01, multivariate analysis; 97% vs. 48%, p = 0.03 for locoregional control, and 95% vs. 59%, p = 0.05 for stoma-free survival). CONCLUSIONS: Our data indicate that normal tissue and tumor tissue may behave similarly with respect to treatment response, since high-grade acute organ toxicity during radiochemotherapy showed itself to be an independent prognostic marker in our patient population. This hypothesis should be further analyzed by using biomolecular and clinical levels in future clinical trials.

High-grade acute organ toxicity as positive prognostic factor in primary radio(chemo)therapy for locally advanced, inoperable head and neck cancer.

PURPOSE: To test for a possible correlation between high-grade acute organ toxicity during primary radio(chemo)therapy and treatment outcome in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: From 05/1994 to 01/2009, 216 HNSCC patients were treated with radio(chemo)therapy in primary approach. They received normofractionated (2 Gy/fraction) irradiation including associated nodal drainage sites to a cumulative dose of 70 Gy. 151 patients received additional concomitant chemotherapy (111 patients 5-fluorouracil/mitomycin C, 40 patients cisplatin-based). Toxicity during treatment was monitored weekly according to the Common Toxicity Criteria (CTC), and any toxicity grade CTC >or= 3 of mucositis, dysphagia or skin reaction was assessed as high-grade acute organ toxicity for later analysis. RESULTS: A statistically significant coherency between high-grade acute organ toxicity and overall survival as well as locoregional control was found: patients with CTC >or= 3 acute organ toxicity had a 5-year overall survival rate of 44% compared to 8% in patients without (p < 0.01). Thereby, multivariate analyses revealed that the correlation was independent of other possible prognostic factors or factors that may influence treatment toxicity, especially concomitant chemotherapy and radiotherapy technique or treatment-planning procedure. CONCLUSION: These data indicate that normal tissue and tumor tissue may behave similarly with respect to treatment response, as high-grade acute organ toxicity during radio(chemo)therapy showed to be an independent prognostic marker in the own patient population. However, the authors are aware of the fact that a multivariate analysis in a retrospective study generally has statistical limitations. Therefore, their hypothesis should be further analyzed on biomolecular and clinical levels and other tumor entities in prospective trials.

High-grade acute organ toxicity during preoperative radiochemotherapy as positive predictor for complete histopathologic tumor regression in multimodal treatment of locally advanced rectal cancer.

PURPOSE: To test for a possible correlation between high-grade acute organ toxicity during preoperative radiochemotherapy and complete tumor regression after total mesorectal excision in multimodal treatment of locally advanced rectal cancer. PATIENTS AND METHODS: From 2001 to 2008, 120 patients were treated. Preoperative treatment consisted of normofractionated radiotherapy at a total dose of 50.4 Gy, and either two cycles of 5-fluorouracil (5-FU) or two cycles of 5-FU and oxaliplatin. Toxicity during treatment was monitored weekly, and any toxicity CTC (Common Toxicity Criteria) >or= grade 2 of enteritis, proctitis or cystitis was assessed as high-grade organ toxicity for later analysis. Complete histopathologic tumor regression (TRG4) was defined as the absence of any viable tumor cells. RESULTS: A significant coherency between high-grade acute organ toxicity and complete histopathologic tumor regression was found, which was independent of other factors like the preoperative chemotherapy schedule. The probability of patients with acute organ toxicity >or= grade 2 to achieve TRG4 after neoadjuvant treatment was more than three times higher than for patients without toxicity (odds ratio: 3.29, 95% confidence interval: [1.01, 10.96]). CONCLUSION: Acute organ toxicity during preoperative radiochemotherapy in rectal cancer could be an early predictor of treatment response in terms of complete tumor regression. Its possible impact on local control and survival is under further prospective evaluation by the authors' working group.

Nasopharyngeal carcinoma in adults: treatment results after long-term follow-up with special reference to adjuvant interferon-beta in undifferentiated carcinomas.

PURPOSE: Nasopharyngeal carcinomas (NPC) are radiosensitive, and radiotherapy is the standard curative treatment. Furthermore, it has been shown that combined radiochemotherapy improves prognosis in locally advanced stages. Further encouraging results have been obtained with adjuvant interferon-beta after primary radio(chemo)therapy in childhood undifferentiated NPC. Aim of the present study was to evaluate the treatment results after long-term follow-up after radio(chemo)therapy for adult NPC with special reference to patients with undifferentiated carcinomas treated with adjuvant interferon-beta. PATIENTS AND METHODS: From 02/1992 to 07/2008, 26 adult patients with NPC without distant metastases were treated (17 squamous cell carcinomas, 9 undifferentiated carcinomas). The treatment concepts changed over the years: 13 patients were treated with radiotherapy alone, 13 patients received combined radiochemotherapy. Additionally, six patients with undifferentiated carcinomas were treated with adjuvant interferon-beta after radiochemotherapy for 6 months. RESULTS: After a median follow-up of 96 months, 17 patients remain alive. Collectively, our 5-year overall-survival and loco-regional control rates were 74% (radiochemotherapy 81%, radiotherapy alone 68.5%) and 87% (radiochemotherapy 100%, radiotherapy alone 72.7%), respectively. All treatment regimens used were feasible; especially, adjuvant interferon-beta was applied as provided without high grade toxicity. All patients with undifferentiated carcinomas treated with adjuvant interferon-beta stayed alive until the end of the follow-up. CONCLUSION: In summary, our data affirm that NPC in adults are curable by primary radio(chemo)therapy. Furthermore, our data indicate that adjuvant interferon-beta application in undifferentiated NPC in adults is feasible and shows promising results. Further prospective clinical trials are needed to finally establish adjuvant interferon beta in curative treatment of adult NPC.