Is urinary tract cancer linked to air quality?

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Is urinary tract cancer linked to air quality?

Macrohematuria (flesh-washed urine) is the typical finding of esophytic bladder cancer. The presence of an intravesical mass can favor the stagnation of urine with the development of infectious pictures in the bladder and ureters with consequent dysuria, stranguria, pollakiuria and bladder tenesmus.

Invasion of the uretero-cystic junction can lead to ureteral obstruction and cause intense pain in the hips. In the subject over the age of 50, suprapubic ultrasound methods implemented for the investigation of urinary obstruction from benign prostatic hyperplasia can reveal asymptomatic papillary lesions that protrude into the bladder.

Invasion of the nerve plexuses can cause intense pain or erectile dysfunction. Enteric, anal, or vaginal fistulas are rare and indicative of advanced disease. Very rarely, the first symptoms are due to metastatic lesions. The presence of macrohematuria, especially in the presence of clots, is a sensitive index of bleeding in the excretory tract.

In this sense, once benign cystitis and urinary lithiasis have been excluded, bladder carcinoma must always be suspected, especially in subjects over the age of 50, smokers and men. Renal ultrasonography, useful in ruling out renal and pelvic changes, and a cytological urine test should be done.

This last examination has a high sensitivity and allows to identify the neoplastic cells of exfoliation; in case of positivity, cystoscopy must be performed, a method capable of highlighting the neoplastic mass and taking biopsy samples.

The study: Air pollution exposure and bladder, kidney and urinary tract cancer risk: A systematic review, published on the: Environmental pollution, said: "Exposure to outdoor air pollution has been linked to lung cancer, and suspicion arose regarding bladder, kidney, and urinary tract cancer (urological cancers).

However, most of evidence comes from occupational studies; therefore, little is known about the effect of exposure to air pollution on the risk of urological cancers in the general population. We systematically searched Medline, Scopus, and Web of Science for articles investigating the associations between long-term exposure to air pollution and the risk of urological cancer (incidence or mortality).

We included articles using a specific air pollutant (PM10, PM2.5,…) or proxies (traffic, proximity index…). We assessed each study's quality with the Newcastle-Ottawa scale and rated the quality of the body of evidence for each pollutant-outcome with the GRADE approach.

The different study methodologies regarding exposure or outcome prevented us to perform a meta-analysis. Twenty articles (four case-control, nine cohort, and seven ecologic) met our inclusion criteria and were included in this review: eighteen reported bladder, six kidney, and two urinary tract.

Modeling air pollutants was the most common exposure assessment method. Most of the included studies reported positive associations between air pollution and urological cancer risk. However, only a few reached statistical significance (e.g.

for bladder cancer mortality, adjusted odds-ratio of 1.13 (1.03-1.23) for an increase of 4.4 μg.m-3 of PM2.5). Most studies inadequately addressed confounding, and cohort studies had an insufficient follow-up. Overall, studies suggested positive (even though mostly non-significant) associations between air pollution exposure and bladder cancer mortality and kidney cancer incidence. We need more studies with better confounding control and longer follow-ups.