Dr. G. S. Bhattacharyya is consultant at the Chittaranjan National Cancer Institute, Kolkata and in-charge of the Department of Medical Oncology of the Fortis Hospital, in Anandapur, Kolkataand of the Department of Medical Oncology in the AMRI Hospital,of Dhakuria, Kolkata

He is a member of many international associations such as the American Association of Cancer Research (AACR), the Tumor Microenvironment Working Group (TME), the European Association of Cancer Research (EACR), the European Society for Medical Oncology (ESMO), the Society for Translational Oncology (STO), the American School of Clinical Oncology (ASCO), the Breast International Group (BIG), the International Cardio-Oncology Society (ICOS), the International Society for Pharmacoepidemiology (ISPE), the International Society of Pharmacovigilance (ISoP), the Oncology Outcome Research Group and Asian Consortium and ISPOR (International Society For Pharmacoeconomics and Outcomes Research)

He also held the following positions : • Advisory Council Member BIG (Breast International Group) o National Council Member BIG (Breast International Group) o BIG Translational and Bio-repository member o Chairman, Emerging Country Task Force member BIG o Committee member BIG – TNBC • Member of the Developing Country Task Force – ESMO o ESMO Panel Member (European Society for Medical Oncology) • Member International Cardi-Oncological Society (ICOS) o Executive Council Member, International Cardio-Oncology Society (ICOS) • Executive Committee Member for SAARC Oncology • Executive Board Member of Euro Asian Mastology Society (EURAMA) • Member of EUSOMA (The European Society of Breast Cancer Specialists) • Executive Committee Member – Breast Cancer Foundation of India.

Lastly, Dr Bhattacharyya is also the incoming President of Indian Society for Medical and Pediatric Oncology (ISMPO) and part of the executive Committee member of Indian Society of Oncology (ISO) and executive Committee Member of Indian Cooperative Oncology Network (ICON).