Secondary Malignancies: The Cost of Progress.

Background: With advances in treatment of cancer, patients who survive their first malignancy are at risk of developing additional malignancies. Data on the risks of secondary malignancies after treatment of some of the more common cancers are lacking.

Methods: Our prospectively maintained database was queried from 1996 to 2016 to identify patients with breast cancer, colorectal cancer, melanoma, sarcoma, gastric, and pancreatic adenocarcinoma who developed additional malignancies. Predisposing clinical factors were included in our analysis.

Results: We identified 756 patients diagnosed with a solid malignancy who developed a second malignancy, of which 606 (80.1%) had one of the most common treated cancers. 59.5% of patients were women. 810 additional malignancies were identified in the 606 patients with breast and colon cancer being the most common secondary malignancies. Of these 606 patients, 460 (76%) patients had two malignancies; 145 (23.9%) had 3 or more malignancies. 15.2% of patients were diagnosed under the age of 40.63 years. 8.3% patients had a known genetic mutation, with BReast CAncer gene, and Lynch mutations being the most common.

Conclusion: Advances in cancer treatment have led to higher cure rates. These patients should continue surveillance and undergo screening as they may be at risk of developing additional malignancies.