TITLE:
A Comparative Study of the Recurrence Rate in Hypofractionated versus Conventional Postmastectomy Radiation in Breast Cancer
AUTHORS:
Aravindh Sivanandan Anand, Abul Hussain Mirsa, Amina Basheer
KEYWORDS:
Breast Cancer, Post Mastectomy Radiation, Conventional, Hypofractionation, Recurrence Rate, Acute Toxicity
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.12 No.12,
December
27,
2021
ABSTRACT: Background: Treatment options available for breast cancer are Surgery [Breast
conservation surgery (BCS) or Modified radical mastectomy (MRM)]; Radiation
treatment [Conventional radiation treatment or CRT and Hypofractionated
radiation treatment or HRT] and Chemotherapy. In the postmastectomy or post lumpectomy
setting, radiotherapy (RT) improves loco-regional control. CRT for breast
includes 50 Gy in 25 fractions (2 Gy per fraction) and HRT
includes 42.5 Gy in 16 fractions (2.7 Gy per fraction) or extreme hypofractionation
like 26 Gy in 5
fractions.
Alpha/beta value for breast is less, so HRT is ideal for breast. So, there will
be good loco-regional control, without increased normal tissue damage. This
study aims to identify recurrence rate and toxicity in breast cancer patients
treated using conventional and hypofractionated postmastectomy radiotherapy
among Indian population. Primary objective: To assess recurrence rate of
disease in breast cancer patients treated using hypofractionated postmastectomy
radiation and to compare it with breast cancer patients treated using
conventional postmastectomy radiation. Secondary objective: To assess
the toxicity in hypofractionation and conventional fractionation arm. Methods: This is a prospective observational study conducted in Department of
Radiation Oncology from December 2017 to June 2019. Radically treated breast
cancer patients who received radiation treatment either conventional or
hypofractionated as one of the treatment modalities were included in the study.
Data were collected using a structured proforma, history and physical
examination, master file of the patients, lab results and the imaging reports,
written informed consent form, ECOG performance status scale (Eastern
Cooperative Oncology Group), RTOG (Radiation
Therapy Oncology Group) Acute Radiation Morbidity Scoring Schema. Patients
were monitored for 18 months to identify recurrence rate and toxicity in each
arm. Results and discussion: A total of 241 patients were enrolled into
this study, among them 175 patients (73%) were given hypofractionation
radiotherapy and 66 patients (27%) were given conventional radiotherapy. In hypofractionation arm, recurrence was found in 14
patients (8%), of which, 3 were local recurrences [chest wall] and 11 were
systemic recurrences, while in conventional arm, recurrence was found in 4
patients (6%) and all of them were systemic recurrences. Recurrence rate in hypofractionation arm was 8% and
in conventional arm was 6.10%. The Kaplan Meier curve
shows no significant difference between the two arms with p value = 0.76. Acute
toxicities assessed were dermatitis, esophagitis and pneumonitis. Among acute
dermatitis, 4 patients had grade 3 and 2 patients had grade 4 in hypofractionation
arm, while in conventional arm, 7 patients had grade 3 and 1 patient had grade
4. Grade 1 and 2 together versus grade 3 and 4 acute dermatitis showed a
statistically significant difference between the two arms, with more acute
toxicity in the conventional arm. Among acute esophagitis, 1 patient had grade
3 and no patients had grade 4 in hypofractionation arm; while in conventional
arm, no grade 3 and grade 4 acute esophagitis were found. Among acute
pneumonitis, 2 patients had grade 3 and 1 patient had grade 4 in
hypofractionation arm, while in conventional arm, 1 patient had grade 3 and no
patients with grade 4 were found. Grade 2 and grade 3 acute lung toxicities
were found in patients with central lung distance more than 1.5 cm. Conclusion: It was found that the recurrence rate of hypofractionation radiotherapy was
comparable to conventional fractionation radiotherapy. With respect to acute
dermatitis, grade 1 and grade 2 were significantly more in conventional than
hypofractionation arm. Hypofractionated radiotherapy is an equally effective
option to conventional radiotherapy and should be encouraged, especially for
developing countries like India where the resource is limited, and the
incidence of tumour is high.