Metachronous and Synchronous Occurrence of 5 Primary Malignancies in a Female Patient between 1997 and 2013: A Case Report with Germline and Somatic Genetic Analysis

The number of patients with multiple primary malignancies has been increasing steadily in recent years. In the present study, we describe a unique case of an 81-year-old woman with 5 metachronous and synchronous primary malignant neoplasms. The patient was first diagnosed with an endometrium adenocarcinoma in 1997 and a colon adenocarcinoma in 2002. Eleven years after her colon surgery, in 2013, the patient presented with 3 other primary malignancies within a 4-month time span: an invasive malignant melanoma on the lower leg, an invasive mucinous breast carcinoma in the right breast, and a pleomorphic spindle cell sarcoma on the left upper arm. Subsequent routine medical checkups in 2013–2017 revealed no metastases of the primary malignancies. The patient mentioned a familial aggregation of malignant tumors, including 2 sisters with breast cancer and a brother with lung cancer. Interestingly, next-generation sequencing analysis of the patient's blood sample detected no mutations in the BRCA1, BRCA2, TP53, PTEN, CDH1, PALB2, RAD51C, RAD51D, MLH1, MSH2, MSH6, PMS2, EPCAM, APC, MUTYH, STK11, BMPR1A, SMAD4, PTEN, POLE, POLD1, GREM1, and GALNT12 genes. Therefore, whole genome sequencing is warranted to identify cancer-related genetic alterations in this patient with quintuple primary malignancies.