Table 2. Distribution of SCCA patients with and without multiple malignancies.

Characteristics	Number
Total number of patients	46
Patients with prior IPM	9a (19.6%)
Total prior malignancies	14
Breast	4
Colorectal	3
Endometrial	2
Vulvar	1
Hepatocellular	1
Chronic lymphocytic leukemia	1
Multiple myeloma	1
Pancreatic	1
Patients with SCCA only	28 (60.9%)
Patients with SPM after index SCCA	9b (19.6%)
Total subsequent malignancies	12
Lung	8
Non-small cell	6
Small cell	2
Breast	2
Pancreatohepatobiliary	1
Thyroid papillary	1

^a, one patient had 4 cancers prior to their SCCA diagnosis [colon (IPM), uterine, rectal, chronic lymphocytic leukemia]. Two patients with a prior IPM had a third cancer, within three months of SCCA diagnosis [patient 1: endometrial (IPM) and multiple myeloma; patient 2: vulvar (IPM) and pancreatic]; ^b, two patients had two metachronous SPMs (patient 3: 2 breast primaries; patient 4: 2 NSCLC primaries). One patient had one synchronous and one metachronous SPM (patient 5: synchronous NSCLC and metachronous small cell lung cancer). One patient had one synchronous SPM (NSCLC). IPM, index primary malignancy; SCCA, squamous cell carcinoma of the anus; SPM, second primary malignancy.