Radiobiological modeling of acute esophagitis after radiation therapy of head, neck, and thorax tumors: The influence of chemo-radiation.

Aim: The aim of this study was to evaluate the performance of various radiobiological models in predicting the occurrence of acute esophagitis (AE) during radiation therapy (RT) of head, neck, and thoracic tumors with concurrent and sequential chemotherapy. According to recent studies, the probability of AE following RT by normal tissue complication probability models is predictable. Materials and Methods: A total of 100 patients with nasopharynx, larynx, Hodgkin's lymphoma, spinal metastases, and oral cavity and lung tumors were included in the study. Half of these patients were treated by concurrent chemo-radiotherapy (Con. CRT) and the other half were treated by radiotherapy alone or sequential chemo-radiotherapy (RT + seq. CRT). Radiobiological models of several types were used as follows,: Lyman-generalized equivalent uniform dose (gEUD), Lyman-MED, log-logistic, logit, and logistic. Parameters were estimated using maximum likelihood estimation, and models were compared using Akaike information criteria. Results: Based on follow-up data, the behavior of dose-response curves differed markedly between the Con. CRT and RT + seq. CRT groups. The best fit with clinical results was offered by the Lyman-MED model for the Con. CRT group and the Lyman-gEUD model for the RT + seq. CRT group. Depending on the model used, the parameter of D50 was considerably lower (up to three times) in the Con. CRT group compared to the RT + seq. CRT group. Conclusions: The incidence of AE significantly differed between the two treatment groups in all the models. New parameter estimates could be used for predicting the probability of acute esophagitis after chemo-RT.

Impact of tumor length on survival for patients with resected esophageal cancer.

BACKGROUND: Tumor length in patients with esophageal cancer (EC) has recently received great attention. However, its prognostic role for EC is controversial. The purpose of our study was to characterize the prognostic value of tumor length in EC patients and offer the optimum cut-off point of tumor length by reliable statistical methods. MATERIALS AND METHODS: A retrospective analysis was conducted on 71 consecutive patients with EC who underwent surgery. ROC curve analysis was used to determine the optimal cut-off point for tumor length, measured with a handheld ruler after formalin fixation. Correlations between tumor length and other factors were surveyed, and overall survival (OS) rates were compared between the two groups. Potential prognostic factors were evaluated by univariate Kaplan-Meier survival analysis. A P value less than 0.05 was considered significant. RESULTS: There were a total of 71 patients, with a male/ female divide of 43/28 and a median age of 59. Characteristics were as follows: squamous/adenocarcinoma, 65/6; median tumor length, 4 (0.9-10); cut-off point for tumor length, 4cm. Univariate analysis prognostic factors were tumor length and modality of therapy. One, three and five year OS rates were 84, 43 and 43% for tumors with ≤4cm length, whereas the rates were 75, 9 and 0% for tumors >4 cm. There was a significant association between tumor length and age, sex, weight loss, tumor site, histology, T and N scores, differentiation, stage, modality of therapy and longitudinal margin involvement. CONCLUSIONS: Future studies for modification of the EC staging system might consider tumor length too as it is an important prognostic factor. Further assessment with larger prospective datasets and practical methods (such as endoscopy) is needed to establish an optimal cut-off point for tumor length.

Impact of postoperative chemoradiotherapy and chemoradiotherapy alone for esophageal cancer in North-West Iran.

BACKGROUND: To investigate the role of surgical treatment for locally advanced esophageal cancer, we compared the outcomes of chemoradiotherapy alone (CRT) to postoperative chemoradiotherapy (S/CRT), using, Regional Radiotherapy Center, database. MATERIALS AND METHODS: This retrospective study was conducted in North-West of Iran, included of 255 consecutive patients with esophageal cancer. Eligible operable and non-operable, were treated with S/CRT and CRT respectively. Radiotherapy (RT) was delivered at 1.8-2 Gy/day for five consecutive days in a given week. Chemotherapy (CT) consisted of cisplatin and 5-fluorouracil. RESULTS: From March 2006 to March 2011 255 patients: male/female 129/96, median age 68 (35-90), squamous/adeno 213/12, received CRT /S+CRT 166/59, median radiation dose 45 ± 13.6 Gy, Median survival 13.5 (11-15), overall survival (OS) One/ Two/Three 57/21/16%, Died/alive 158/97, Univariate analysis prognostic factors: age/stag/differentiation/dose of RT/fraction/treatment, Multivariate analysis predictor factor: dose of RT/fraction. CONCLUSIONS: Although this treatment offers some possibility for improvement of patients with esophageal cancer, there remains a significant need for development of new drug and new therapeutic approaches that can substantially impact survival.

Survival in patients treated with definitive chemo- radiotherapy for non-metastatic esophageal cancer in north- west iran.

BACKGROUND: Areas of Iran have among the highest incidences of esophageal cancer in the world. Definitive chemo-radiotherapy (DCRT) is used for locally advanced esophageal cancer and for inoperable tumors asan alternative to surgical treatment. MATERIALS AND METHODS: This retrospective study was conducted in North- West Iran 2006-2011, including 267 consecutive patients with non-metastatic esophageal cancer. Eligible inoperable patients were treated with DCRT or definitive radiotherapy (DRT) alone. Radiotherapy (RT) was delivered at 1.8-2 Gy/day for five consecutive days in a given week. Chemotherapy (CT) consisted of cisplatin and 5-fluorouracil. RESULTS: The median survival was 12.7 months with 1, 3 and 5 year survival rates of 55%, 18% and 11%, respectively. On univariate analysis, relations with age at diagnosis (p=0.015), N-stage (p=0.04), total dose of RT (p=0.001), fraction (p<0.001), Gap status (p=0.025), chemotherapeutic regimens (P=0.027), and 5-Fu Mg/m2 (P=0.004) were apparent. Comparing DCRT to DRT, there was a significant difference in survival. Multivariate analysis was performed for comparison between DCRT and DRT showed significant association with age group ≥65 to <65 (P=0.02; OR: 1.46), the total RT dose (Gy) ≥50 to <50 (P=0.01; OR: 0.65) and the fraction group ≥25 to <25 (P=<0.001; OR: 0.54). CONCLUSIONS: The survival rates of esophageal cancer treated with DCRT in North West of Iran is poor; therefore, early detection and improved treatment methods, with clinical trials are a high priority.

Survival rate and prognostic factors of esophageal cancer in east Azerbaijan province, North-west of Iran.

BACKGROUND: Esophageal cancer in Iran is the sixth most common cancer and is particularly important in east Azerbaijan. The aim of this study was to calculate survival rates and define prognostic factors in esophageal cancer patients. METHODS: In this study, all patients with esophageal cancer registered in the Radiation Therapy Center, during March 2006 to March 2011, were analyzed and followed up for vital status. Data were analyzed using the Kaplan-Meier method and the Cox proportional hazard models. RESULTS: Out of 532 patients, survival information was available for 460, including 205 (44/5%) females and 255 (55/4%) males. The mean age was 65.8±12.2, ranging from 29 to 90 years at the time of diagnosis. 1- , 3- and 5-year survival rates after diagnosis were 55%, 18% and 12%, respectively, with a median survival time of 13.2 ± .7 (CI 95%=11.8-14.6) months. In the univariate analysis, age (P=0/001), education (P=0/001), smoking status (P= 0/001), surgery (P=0/001), tumor differentiation (P=0/003) and tumor stage (P=0/001) were significant prognostic factors. Tumor morphology, sex, place of residence, tumor histology and tumor location did not show any significant effects on the survival rate. In multivariate analysis, age (P=0/003), smoking (P=0/01) and tumor stage (P=0/001) were significant independent predictors of survival. CONCLUSION: In summary, prognosis of esophageal cancer in North West of Iran is poor. Therefore, reduction in exposure to risk factors and early detection should be emphasized to improve survival.