Common European Mitochondrial Haplogroups in the Risk for Radiation-induced Subcutaneous Fibrosis in Breast Cancer Patients.

AIMS: The contribution of mitochondrial DNA (mtDNA) variations to clinical radiosensitivity is largely unknown. In the present study, we evaluated the association between mtDNA haplogroups and the risk of radiation-induced subcutaneous fibrosis after postoperative radiotherapy in breast cancer patients. MATERIALS AND METHODS: Subcutaneous fibrosis was scored according to the Late Effects of Normal Tissue-Subjective Objective Management Analytical (LENT-SOMA) scale in 286 Italian breast cancer patients who received radiotherapy after breast-conserving surgery. Eight mtDNA single nucleotide polymorphisms that define the nine major haplogroups in the European population were determined by polymerase chain reaction restriction fragment length polymorphism analysis on genomic DNA extracted from peripheral blood. RESULTS: In a Kaplan-Meier analysis evaluated by the Log-rank test, carriers of haplogroup H were found to be at lower risk of grade ≥2 subcutaneous fibrosis (P = 0.018) compared with all other haplotypes combined. In the multivariate Cox regression analysis adjusted for clinical factors (body mass index, breast diameter, adjuvant treatment, dose per fraction, radiation type and acute skin toxicity), haplogroup H emerged as a protective factor for moderate to severe radiation-induced fibrosis at a nominal significance level (hazard ratio: 0.50, 95% confidence interval 0.27-0.92, P = 0.027), which did not survive correction for multiple testing. CONCLUSIONS: Our results suggest a protective effect of the mitochondrial haplogroup H in the development of radiation-induced fibrosis in breast cancer patients. However, the loss of statistical significance after correction for multiple comparisons and the lack of an independent validation cohort make our findings preliminary, requiring further confirmation in large-scale prospective studies.

Concurrent chemo-radiotherapy in elderly patients: tolerance and compliance in a series of 137 patients.

INTRODUCTION: Aggressive cancer treatment is a challenge in elderly patients. The present study aims to assess tolerance in terms of acute toxicity and compliance of concurrent chemo-radiotherapy (cCRT) in a series of patients aged ≥70 years. MATERIALS AND METHODS: Clinical records of patients aged ≥70 years who underwent cCRT between January 2005 and December 2013 were reviewed. Concurrent CRT had curative intent in 134 patients (97.8 %) and palliative intent in 3 patients (2.2 %). Chemotherapy (CT) drugs and schedule were selected according to tumor histology. Radiotherapy median dose was 45.0 Gy (range 11-70 Gy) for curative purposes and 54 Gy (range 40-56 Gy) for palliative purposes. Incidence of acute toxicity and compliance to cCRT were analyzed and correlated with age, Karnofsky Performance Status (KPS), and Charlson Comorbidity Index (CCI). RESULTS: Overall, 137 patients, 82 males (60 %) and 55 females (40 %), median age 74 years (range 70-90 years) were analyzed. Concurrent CRT schedule was completed by 132 patients (96.4 %). Thirty-one of these patients (23.5 %) temporarily interrupted treatment. Hematological toxicity with grade ≥1 was observed in 25 patients (18.2 %), gastrointestinal toxicity in 55 (40.1 %), and genitourinary in 13 (9.5 %). Mucositis with grade ≥1 was recorded in 19 patients (13.9 %). No statistical significant correlation between KPS, CCI, and toxicity was found. A correlation trend between mucositis and patient age (p = 0.05) was observed. CONCLUSION: Concurrent CRT for elderly was feasible and quite well tolerated. Great attention in prescribing CT dose should be paid to limit acute toxicity.