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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. [ABSTRACT FROM AUTHOR]

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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. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]