Table 1. Baseline characteristics of patient population.

Characteristic	All patients No. [%]	Patients with prior IPM, N [%]	Patients with SCCA only, N [%]	Patients with SPM after index SCCA, N [%]
Total number of patients	46	9	28	9
Gender
Male	14 [30]	2 [22]	9 [32]	3 [33]
Female	32 [70]	7 [78]	19 [68]	6 [67]
Race
White	33 [72]	9 [100]	20 [71]	4 [44]
Black	6 [13]	0	4 [14]	2 [22]
Hispanic	7 [15]	0	4 [14]	3 [33]
Age (mean ± SD)	58±9.2	63±8.7	58±9.6	56±7.3
Stage of SCCA at diagnosis
Tis	1 [2]	1 [11]	0	0
I	3 [7]	1 [11]	1 [4]	1 [11]
II	21 [46]	5 [56]	12 [43]	4 [44]
III	18 [39]	2 [22]	12 [43]	4 [44]
IV	3 [7]	0	3 [11]	0
Smoking status
Active smoker at SCCA diagnosis	8 [17]	1 [11]	6 [21]	1 [11]
Former smoker	16 [35]	3 [33]	9 [32]	4 [44]
Never smoked	22 [48]	5 [56]	13 [46]	4 [44]

IPM, index primary malignancy; SCCA, squamous cell carcinoma of the anus; SPM, second primary malignancy; SD, standard deviation.