148P Breast cancer as second primary malignancy in cancer survivors: Experience from a Tertiary Cancer Center in India

Abstract

Improvement in cancer detection and advances in treatment have resulted in an increasing number of cancer survivors. They are at risk of sequelae such as second primary malignancy (SPM) which can be due to variety of factors like genetic, environmental and pervious treatment. Being one of the most common malignancies detected in females worldwide, breast cancer presenting as SPM is increasingly reported. The patients treated in the breast cancer clinic, Department of Medical Oncology at Regional Cancer Center, a leading tertiary cancer center in South India were studied during the period January 2017 to December 2019. Among 3500 patients, 25 presented as SPM. Details of the patients were noted from the case records. Those patients with prior histologically proven breast cancer were excluded. Among the 25 patients, 24 were females and one was male. The most common primary malignancy was carcinoma thyroid (5 cases) followed by osteosarcoma and carcinoma endometrium (3 cases each).The median time interval between primary and second malignancy was 9 years (range 2-26 years). The median age at diagnosis of second malignancy was 59 years (range 39-79 years) and 76% of the patients were more than 50 years of age. Most of the patients presented with early stage disese (19 were stage 1 or 2), 6 were stage 3 and none was metastatic at presentation (9 triple negative, 9 hormone receptor+ and 7 HER2+). All patients received curative treatment based on the stage and tumor biology. In those who had received anthracyclin agents as part of their initial treatment, the same was avoided in the management of SPM. All of the HER2 positive patients received anti HER2 agents and hormone positive patients received endocrine agents based on the menopausal status. Patients who were on targeted agents were allowed to continue the same with adequate monitoring. In patients who had received radiation previously, reirradiation was given with the dose adjustments. Among the 25 patients, two progressed after initial treatment and further follow up is needed to to comment on the survival. The possibility of SPM must always be considered in the follow-up visit of cancer survivors. Tailoring of treatment may be required based on the previous therapy.