Sex Disparities in Cancer Mortality: The Risks of Being a Man in the US
December 28, 2012
A novel descriptive epidemiologic study that will be published in the Journal of Urology is the first study to quantify the differential mortality rates between sexes from non-gender-specific cancers and compare their cancer stage distribution. This study hypothesized that men die more commonly from their cancers than their female counterparts, even after the increased male incidence is accounted for.
Between 1975 and 2004, the National Institutes of Health reported the total cancer burden in the US was higher in males compared to females with an incidence ratio of 1.14; when sex-specific cancers were excluded, the ratio increased to 1.77. Moreover, the yearly male to female cancer mortality ratio was 1.89.
The authors determined that over the last 10 years, the number of men diagnosed with cancer has consistently been 1.5 times greater than the rate for women. While the overall mortality rates attributable to cancer have decreased over 10% for both men and women, the mortality rate for men still exceeds that for women, even for the same type of cancer. While a descriptive study does not explain the reasons for gender differences in oncologic outcomes, previous studies have highlighted differences in modifiable risk factors, differences in healthcare utilization, and intrinsic biological differences between the sexes. In the US, 27% of men report not being evaluated by a physician within the last year compared to 14% of women.
In summary, the authors concluded that men develop and die more often from cancers that should affect men and women equally. However, the number of men diagnosed with non-gender-specific cancer is 50% higher than the number of women diagnosed with cancer. After controlling for higher male incidence of cancers, men have a 12.6% higher mortality rate than women for the same types of cancer.
Reference: Najari BB, Rink M, Li PS, Karakiewicz PI, Scherr DS, Shabsigh R, Meryn S, Schlegel PN, Shariat SF. Sex disparities in cancer mortality: the risks of being a man in the US. J Urol 2012, doi:10.1016/j.juro.2012.11.153.
Reduced Lung Cancer Mortality with CT Screening
May 31, 2012
Lung cancer remains the most common cause of cancer-related death in men worldwide, and accounts for more deaths than prostate, colorectal, and pancreas combined. It is estimated that 90% of lung cancer deaths among men are due to smoking. Given the aggressive nature of lung cancer, there is a need for effective screening to detect early disease which is more responsive to treatment and potentially curable. Recently, the results of the National Lung Screening Trial* (NSLT) was published. The study examined whether screening with low-dose CT could reduce mortality from lung cancer. In this U.S. multicenter trial 53,454 persons at high risk for lung cancer were randomly assigned to undergo three annual screenings with either low-dose CT or single-view chest radiography. Eligible participants were between ages 55 and 74 and had a history of at least 30 pack-years; former smokers had quit within the previous 15 years. Data were compiled on cases of lung cancer and lung cancer deaths. A 20% decrease in lung cancer mortality was observed in the low-dose CT group as compared with the radiography group. The number needed to screen with low-dose CT to prevent one death from lung cancer was 320.
The research team of the trial concluded that the decrease in lung cancer mortality must be weighed against the harms related to false positive screening results, which include radiation exposure, psychological stress, and invasive diagnostic procedures for benign disease. The costs of the screening test and subsequent diagnostic evaluation also raises a significant concern. Currently, it is estimated that 7 million U.S. adults meet the entry criteria for the NLST, and 94 million U.S. adults are current or former smokers. A national screening program targeting either population would be very expensive.
Recently, the U.S. National Comprehensive Cancer Network (NCCN), released lung cancer screening guidelines. Based on the results of the NSLT, the NCCN recommends lung cancer screening with annual low-dose CT for patients who meet the NSLT inclusion criteria as stated above. Additional studies are necessary to help determine if low-dose CT should be recommended to all smokers.
Reference: The National Lung Screening Trial Research Team. Reduced Lung-Cancer Mortality with Low-Dose Computed Tomographic Screening. N Engl J Med 2011;365:395-409.
Colonoscopy Prevents Colorectal Cancer Deaths
March 12, 2012
Colorectal cancer is the third most common cancer and the fifth leading cause of cancer death in men worldwide. The majority of colorectal cancers arise from adenomatous polyps, which can be detected with screening colonoscopy. Previously, the investigators of the National Polyp Study (NPS), found that colorectal cancer can be prevented by colonoscopic removal of adenomatous polyps. However, it has been unclear if the cancers prevented were those that had the potential to cause death. Recently, Zauber and colleagues reported* the effect of colonoscopic polypectomy on mortality from colorectal cancer. The researchers conducted a long-term prospective study of the NPS cohort of patients to determine the mortality among patients with adenomas removed compared with the expected mortality from colorectal cancer in the general population. The death rate of patients with adenomas was also compared with an internal control group of patients with nonadenomatous polyps. Among 2,602 patients who had adenomas removed, 12 died from colorectal cancer over a median period 15.8 years, compared with 25 expected deaths in the general population, suggesting a 53% reduction in mortality. Mortality from colorectal cancer among patients with adenomatous polyps was similar to those with nonadenomatous during the first 10 years after polypectomy. Thereafter, mortality increased for patients with adenomas, when strict surveillance was not organized by the study’s investigators. The researchers concede several limitations of the study. A small number of skilled endoscopists performed the colonoscopies, thus the observations may not be applicable to a community practice, for which the reported rates of colorectal cancer after polypectomy are higher than those reported in the NPS. The results of the study may not be representative of the general population, since the study was not a randomized, controlled trial. In conclusion, the study’s findings further support the belief that colonoscopic removal of adenomatous polyps prevents colorectal cancer death. The results also underscore the importance of longterm-term surveillance for patients after the initial removal of adenomatous polyps. More randomized, population-based trials are necessary to determine the effectiveness of screening colonoscopy on colorectal cancer mortality.
Zauber AG, et al. Colonoscopic Polypectomy and Long-Term Prevention of Colorectal-Cancer Deaths. N Engl J Med 2012;366:687-96.
Bretthauer M, Kalager M. Colonoscopy as a triage screening test. N Engl J Med 2012;366:759-60.
Testicular Cancer Screening Update
April 28, 2011
The United States Preventive Services Task Force (USPSTF) recently published its updated guidelines on testicular cancer screening and offered a reaffirmation of their previous recommendations from 2004.
With regard to screening for testicular cancer in asymptomatic males, the USPSTF recommendation states that there is inadequate evidence to suggest that screening via either self-examination or clinician examination has a greater yield for detection of testicular cancer. Therefore, this organization recommends against routine screening, as there is no evidence that such screening offers any net benefit, given a low incidence of testicular cancer and excellent treatment outcomes for detected cases. Similarly, these recommendations have been endorsed by the American Academy of Family Physicians, the American Academy of Pediatrics, and the American Cancer Society.
Testicular cancer remains one of most rare forms of cancer in men worldwide, yet is the most common cancer in men ages 15 to 34 years. In the US, the annual incidence is estimated at 5.4 cases per 100,000 men. Most cases of testicular cancer continue to be discovered by young men “accidentally”, or by their sexual partners.
Potential harms associated with screening for testicular cancer include the notion of false-positive results, the creation of significant anxiety and worry in men, and potential unintended harms from diagnostic tests or procedures.
Making a statement to recommend against screening for testicular cancer has led to much debate and concern among clinicians, despite a lack of strong evidence to suggest otherwise. Some clinicians have interpreted this statement as discouragement of patients seeking medical attention for testicular or scrotal symptoms, yet this notion breaches the definition of routing screening, and is not part of the explicit recommendation.
Reference: U.S. Preventive Services Task Force. Screening for Testicular Cancer: U.S. Preventive Services Task Force Reaffirmation Recommendation Statement. Ann Intern Med 2011;154:483-6.
Half of adult males may have HPV
March 17, 2011
A recent study published in the March 1 online edition of the Lancet, found that half of adult males in the United States, Brazil, and Mexico may be infected with the human papillomavirus (HPV). HPV has been linked to cervical cancer and other tumors. The study, funded by the U.S. National Cancer Institute, found that having multiple female or male sex partners significantly increased the risk of HPV infection in males. It also pointed out that about 6 percent of men are newly infected with HPV16 each year.
HPV16 is the virus which causes several cancers in men and cervical cancer in women. In 2009, 32,000 cases of cancers in American men and women were attributable to HPV infection. HPV infection has been tied to cancers of the penis, vulva, anal canal, head and neck, cervix, vagina, oral cavity.
The study was comprised of 1,159 men in the United States, Mexico, and Brazil, who were HIV negative and reported no history of cancer, aged 18 to 70.The researchers found that men who had 50 or more female partners were at 2.4 times increased risk for cancer-causing HPV infection versus one with one or no partners.The risk for men who had at least three male anal sex partners was 2.6 times higher than men with no recent partners.
However, to this point HPV vaccination has been uncommon in males. The cost-benefit ratio of vaccinating men against HPV has not yet been established. It should be noted that as more diseases are prevented through vaccinating males,routine vaccination for both sexes should prove more cost effective.According to various sources, HPV infects over20 million people in the U.S.
These findings should help public health experts, healthcare providers, and key thought leaders determine the value of widespread HPV vaccination of males in the United States and countries around the world.Healthcare providers have been quoted as saying that vaccinating boys and men (as done in Europe and Australia) is an important next step. This would not only protect boys and men from the disease, but as carriers of HPV, vaccination would also protect girls and women.
Reference: The Lancet, Early Online Publication, 1 March 2011. Incidence and clearance of genital human papillomavirus infection in men (HIM): a cohort study. Prof Anna R Giuliano PhD, Ji-Hyun LeeDrPH, William Fulp MS, Prof Luisa L Villa PhD, Prof Eduardo Lazcano PhD, Mary R Papenfuss MS, Martha Abrahamsen MPH, Jorge Salmeron MD, Gabriella M Anic MSPH, Dana E Rollison PhD, Danelle Smith MS
Available on the World Wide Web at: http://annonc.oxfordjournals.org/content/early/2011/01/25/annonc.mdq695.full.pdf+html