. 2017 Sep 7;125(9):097005. doi: 10.1289/EHP1065

Table 1.

Selected characteristics of cutaneous squamous cell carcinoma (SCC) cases and matched controls from the New Hampshire Skin Cancer Study, July 2007–July 2009 ( $n = 949$ ) [ $n (%) or median \pm SD$ unless otherwise indicated].

Characteristic	SCC cases	Controls	No rice^a	Any rice^a	$< 1 μ g / L$ water As^b	$\geq 1 μ g / L$ water As^b
Total no.	487	462	224	725	699	242
Gender
Male	293 (60.2)	269 (58.2)	147 (65.6)	415 (57.2)^*	409 (58.5)	152 (62.8)
Female	194 (39.8)	193 (41.8)	77 (34.4)	310 (42.8)	290 (41.5)	90 (37.2)
Reference age (years)
25–40	4 (0.8)	3 (0.6)	1 (0.4)	6 (0.8)^*	5 (0.7)	2 (0.8)
41–50	20 (4.1)	20 (4.3)	4 (1.8)	36 (5.0)	30 (4.3)	9 (3.7)
51–60	107 (22.0)	121 (26.2)	47 (21.0)	181 (25.0)	160 (22.9)	66 (27.3)
61–67	164 (33.7)	137 (29.7)	65 (29.0)	236 (32.6)	225 (32.2)	74 (30.6)
68–70	66 (13.6)	75 (16.2)	39 (17.4)	102 (14.1)	100 (14.3)	40 (16.5)
$> 71$	126 (25.9)	126 (27.3)	68 (30.4)	164 (22.6)	179 (25.6)	51 (21.1)
Education
High school	114 (23.4)	178 (38.5)^***	97 (43.3)	195 (26.9)^***	224 (32.0)	67 (27.7)
College	199 (40.9)	170 (36.8)	82 (36.6)	287 (39.6)	270 (38.6)	95 (39.3)
Graduate or professional	173 (35.5)	114 (24.7)	45 (20.1)	242 (33.4)	204 (29.2)	80 (33.1)
Cigarette smoking^c
Never smoked	215 (44.1)	174 (37.7)	84 (37.5)	305 (42.1)	292 (41.8)	94 (38.8)
Former smoker	215 (44.1)	223 (48.3)	103 (46.0)	335 (46.2)	321 (45.9)	113 (46.7)
Current smoker	57 (11.7)	65 (14.1)	37 (16.5)	85 (11.7)	86 (12.3)	35 (14.5)
Body mass index at 18 y old ( ${kg / m}^{2}$ )
Underweight $< 18.5$	49 (10.1)	52 (11.3)	18 (8.0)	83 (11.4)	71 (10.2)	29 (12.0)
Normal 18.5–24.9	348 (71.5)	332 (71.9)	152 (67.9)	528 (72.8)	501 (71.7)	173 (71.5)
Overweight 25.0–29.9	77 (15.8)	62 (13.4)	44 (19.6)	95 (13.1)	104 (14.9)	35 (14.5)
Obese $> 30.0$	13 (2.7)	15 (3.2)	10 (4.5)	18 (2.5)	23 (3.3)	5 (2.1)
Caloric intake ( $kcal / d$ )^d
Quartile 1: $\leq 1,412$	96 (19.7)	116 (25.1)	76 (33.9)	136 (18.8)***	153 (21.9)	55 (22.7)
Quartile 2: 1,412–1,831	133 (27.3)	115 (24.9)	70 (31.2)	178 (24.6)	189 (27.0)	59 (24.4)
Quartile 3: 1,831–2,328	126 (25.9)	115 (24.9)	44 (19.6)	197 (27.2)	179 (25.6)	59 (24.4)
Quartile 4: $> 2,328$	132 (27.1)	116 (25.1)	34 (15.2)	214 (29.5)	178 (25.5)	69 (28.5)
Water Arsenic ( $μ g / L$ )^b	$0.33 \pm 13.7$	$0.30 \pm 9.0$	$0.33 \pm 6.8$	$0.31 \pm 12.8$	$0.21 \pm 0.22$	$3.82 \pm 21.44$
Urinary Arsenobetaine ( $μ g / L$ )^e	$7.55 \pm 136.9$	$5.30 \pm 87.5$ ^*	$6.51 \pm 119.2$	$6.67 \pm 115.1$	$6.90 \pm 131.4$	$6.04 \pm 51.8$
SCC body site^f
Head or neck	241 (49.5)	—	53 (23.7)	188 (27.7)	178 (25.5)	60 (24.8)
Limbs and trunk	246 (50.5)	—	45 (20.1)	201 (25.9)	177 (25.3)	69 (28.5)
Skin reaction to initial sun exposure^g
Tan	36 (7.4)	95 (20.6)^***	31 (13.8)	100 (13.8)	85 (12.2)	45 (18.6)
Mild burn then tan	242 (49.7)	230 (49.8)	109 (48.7)	363 (50.1)	349 (49.9)	120 (49.6)
Burn then peel	173 (35.5)	108 (23.4)	67 (29.9)	214 (29.5)	216 (30.9)	61 (25.2)
Blister	33 (6.8)	29 (6.3)	16 (7.1)	46 (6.3)	47 (6.7)	15 (6.2)
No. of blistering sunburns
None	237 (48.7)	255 (55.2)^***	116 (51.8)	376 (51.9)	366 (52.4)	125 (51.7)
1	63 (12.9)	60 (13.0)	30 (13.4)	93 (12.8)	93 (13.3)	28 (11.6)
2	27 (5.5)	16 (3.5)	16 (7.1)	27 (3.7)	32 (4.6)	11 (4.5)
$\geq 3$	118 (24.2)	58 (12.6)	37 (16.5)	139 (19.2)	124 (17.7)	50 (20.7)
Tanning lamp use
Yes	151 (31.0)	112 (24.2)^*	46 (20.5)	217 (29.9)^**	193 (27.6)	67 (27.7)
No	336 (69.0)	350 (75.8)	178 (79.5)	508 (70.1)	506 (72.4)	175 (72.3)
Skin color^h
Light	437 (89.7)	353 (76.4)^***	193 (86.2)	597 (82.3)	586 (83.8)	200 (82.6)
Medium	50 (10.3)	108 (23.4)	31 (13.8)	127 (17.5)	113 (16.2)	42 (17.4)

Note: Numbers may not sum to the overall total due to missing data. They were excluded from complete-case analyses. p -Values obtained from $χ^{2}$ , Fisher’s exact, or Wilcoxon rank sum test (as appropriate) comparing sociodemographic and skin cancer risk factors between SCC cases and controls.

^{^a}

Rice consumption derived from the Harvard Food Frequency Questionnaire section on “Breads, Cereals, Starches” using items “Brown rice” and “White rice.”

^{^b}

Eight study participants were missing water arsenic concentrations.

^{^c}

Cigarette smoking status at 1 y prior to the reference or diagnosis date.

^{^d}

Caloric intake quartiles determined from the control subject distribution.

^{^e}

Seventy-six study participants were missing urinary arsenobetaine concentrations.

^{^f}

Among SCC cases only. Numbers will not sum to the overall total due to lack of inclusion of controls.

^{^g}

Sun sensitivity was defined as the reaction to 1 h of sun exposure the first time in the summer.

^{^h}

Self-reported coloring. Natural skin color on areas never exposed to the sun.

$p < 0.05$ ;

^**

$p < 0.01$ ;

^***

$p < 0.001$ .