Incidence of second primary malignant neoplasm in Malwa region of central India.

Background: Advancement in diagnostic and therapeutic modalities lead to increased cancer survivors who have 20% higher risk of developing second primary malignancy (SPM).

Aim: To look for the incidence, epidemiological factors, treatment-related factors, and common risk factors responsible for the development of the SPM in Malwa region.

Materials and Methods: Records of 7709 patients who visited the Department of Oncology between May 2008 and August 2015 were analyzed and looked for the presence of SPM based on Warren and Gates criteria for head and neck and International Agency for Research on Cancer definition for other sites. Data pertaining age at diagnosis of each tumor, gender, site, histology, the duration between primary and secondary tumors, treatment received for each malignancy, smoking and drinking habits, and metastasis sites were recorded.

Results: Of 7709 patients, 56 developed SPM (11 synchronous and 45 metachronous) with an overall incidence of 0.726%. For metachronous SPM, the interval of 10-312 months was observed, with a mean time of 103.32 months (standard deviation 65.9 months). About 71.42% patients with SPM belonged to fifth, sixth, and seventh age decade. The median age of diagnosis for the second primary neoplasm was 57 years (range: 34-85 years). Maximum SPM were observed among head and neck tumors (33.93%) followed by breast (26.78%). The most common sites for SPM are head and neck (32.14%) followed by digestive system (19.64%). Breast as the first or the second location was seen associated with almost all systems. For the treatment of first primary, six received surgery, three received chemotherapy (CT), one received radiotherapy (RT) alone, and rest 46 patients received combined modality. For the treatment of SPM, 37 patients received combined modality, ten received CT, three with RT, and two with surgery while four patients received no treatment. Thirty-two patients had habits of tobacco, smoking and alcohol intake with twenty patients continued these after treatment for the first primary neoplasm.

Conclusions: Patients with breast and head and neck cancer have a higher risk of developing SPM. The possibility of SPM should be considered and excluded during pretreatment evaluation and during follow-up of treated cancer patients.