Bladder and upper urinary tract cancers as first and second primary cancers.

Area of Science:

• Oncology
• Epidemiology
• Cancer Research

Background:

• Previous studies on second primary cancers (SPCs) in urothelial cancers primarily focused on bladder cancer.
• Limited data exists on SPCs for other urothelial sites like the renal pelvis and ureter.
• A bidirectional analysis of urothelial cancers and SPCs is needed.

Purpose of the Study:

• To estimate sex-specific risks for any SPCs following urothelial cancers.
• To determine the risk of urothelial cancers as SPCs after any initial cancer.
• To conduct a two-way analysis for improved interpretation of cancer risks.

Main Methods:

• Utilized standardized incidence ratios (SIRs) to assess bidirectional relative risks.
• Data sourced from the Swedish Cancer Registry spanning 1990-2015.
• Included analysis of urinary bladder, ureteral, and renal pelvic cancers.

Main Results:

• High SIRs for SPCs were observed after male bladder cancer, particularly for ureteral (41.9) and renal pelvic (17.2) cancers.
• Renal pelvic (21.0) and ureteral (20.9) cancers showed the highest association with subsequent bladder cancer.
• Female bladder, ureteral, and pelvic cancers were significantly associated with endometrial cancer.

Conclusions:

• Recurrent urothelial cancers present very high risks, with females exhibiting twice the risk of males.
• Elevated risks persist beyond 5 years, necessitating extended patient follow-up.
• Lynch syndrome-related cancers are linked to female urothelial cancers, warranting clinical attention.