Men’s Health Mythbuster is a section on UrologyTimes.com that explores common statements and beliefs about men’s health and evaluates whether these statements are false.
Mr. Lawlor and Mr. Miller are research assistants and Dr. Albala is medical director at Associated Medical Professionals, Syracuse, NY.
Can the length of a person’s finger tell you anything about their risk for developing prostate cancer?
Although not many have investigated the link between finger length and prostate cancer, there are several studies that have found significant relationships between finger length and the incidence of prostate cancer (BJU Int 2011; 107:591-6; Br J Cancer 2011; 104:175-7). These studies largely focus on the ratio of index finger length (2D) relative to ring finger length (4D). It has been suggested that this 2D:4D ratio can be used as a marker of prenatal androgen exposure (J Biosoc Sci 2007; 39:599-612), with a low 2D:4D ratio being associated with high prenatal testosterone exposure (BJU Int 2011; 107:591-6). In other words, lower prenatal testosterone exposure is associated with a higher likelihood of having longer index fingers, and possibly a reduced likelihood of developing prostate cancer (BJU Int 2011; 107:591-6; Br J Cancer 2011; 104:175-7).
A study published in the British Journal of Cancer collected data over 15 years from 1,524 patients with prostate cancer and 3,044 patients without known prostate cancer. Participants were asked to identify their 2D:4D ratio by comparing their hand pattern to a series of pictures depicting an index finger either shorter than, equal to, or longer than a ring finger. Participants with a greater 2D:4D ratio were found to have a significantly decreased prostate cancer risk than participants with lower 2D:4D ratios (Br J Cancer 2011; 104:175-7).
These findings mimic findings of a similar study that investigated finger length, prostate volume, prostate cancer risk, and PSA values. This study recruited 366 men to undergo a transrectal ultrasound of the prostate, as well as a 12-core prostate biopsy if their PSA value was ≥3 ng/mL. The participants’ digit ratios were measured with calipers (BJU Int 2011; 107:591-6). While no association was found between digit ratio and prostate volume, lower digit ratios were associated with greater PSA values, greater PSA density, greater risk of undergoing prostate biopsy due to elevated PSA, and a greater risk of having prostate cancer (BJU Int 2011; 107:591-6).
However, a study published in the British Journal of Cancer denied the existence of a correlation between 2D:4D ratio and prostate cancer. For the study, 6,258 men participating in the Melbourne Collaborative Cohort Study had their 2D:4D ratio evaluated. Among these men, 686 incident prostate cancer cases were identified. Hazard ratios (HRs) and confidence intervals (CIs) were estimated for a standard deviation increase in 2D:4D ratio. No correlation was detected between 2D:4D ratio (for either hand) and prostate cancer risk overall (HRs 1.00; 95% CIs, 0.92–1.08 for right, 0.93–1.08 for left) (Br J Cancer 2011; 105:438-40).