Table 3. Hazard ratios of the Cox proportional hazard model comparing conditional observed survival of patients with or without PCCRC, and correcting for sex, tumor behavior (in situ vs. invasive), tumor location (right and middle vs. others), age, presence of multiple tumors (synchronous and metachronous) and level of staging (continuous explanatory variable). The uncorrected hazard ratio for interval cancer is also provided.

Factor	Hazard ratio	95 % C. I.	P value
Sex
Male	Reference
Female	0.68	0.64 – 0.73	< 0.0001
Tumor type
In situ	Reference
Invasive	1.26	1.07 – 1.47	0.0048
Tumor location
Others	Reference
Right/middle	1.14	1.06 – 1.23	0.0003
Age
< 45 years	Reference
45 – 54 years	1.04	0.76 – 1.55	0.84
55 – 64 years	1.72	1.19 – 2.47	0.0042
65 – 74 years	2.57	1.73 – 3.67	< 0.0001
75 – 84 years	5.12	3.59 – 7.32	< 0.0001
> 84 years	10.5	7.23 – 15.2	< 0.0001
Multiple (synchronous)
No	Reference
Yes	1.10	0.87 – 1.39	0.42
Multiple (metachronous)
No	Reference
Yes	1.47	1.18 – 1.84	< 0.0001
Staging	1.07	1.06 – 1.08	< 0.0001
Interval cancer
Corrected
No	Reference
Yes	1.35	1.18 – 1.53	< 0.0001
Uncorrected
No	Reference
Yes	1.38	1.22 – 1.57	< 0.0001