“The rise of penis cancer: Cases soar by 20%, amidst fears that symptoms are being misdiagnosed as STDs,” reports the Mail Online.
The news follows a recently published study of long-term trends in incidence and mortality rates of penile cancer in England from 1979 to 2009, as well as survival trends from 1971 to 2010.
The study found that the incidence (number of new cases each year) of penile cancer increased by 20% over the period. However, the number of deaths due to penile cancer decreased by 19%. Survival rates of at least one year increased from 76.2% to 87.1%, and five-year survival increased from 61.4% to 70.2%.
The reasons for these changes were not investigated, but the researchers suggest a range of plausible reasons, including the fact men are living longer and are therefore more likely to develop cancer, as well as improving medical practices, meaning cases are now picked up sooner than they were in the 1970s.
Cancer of the penis is not one of the most common cancers, but this study highlights the need for greater awareness of the condition. Early diagnosis may lead to successful treatment, such as penile-preserving procedures.
Where did the story come from?
The study was carried out by researchers from University College Hospital, London; Queen Mary University of London; London School of Hygiene and Tropical Medicine; the Office of National Statistics; and the Christie Hospital, Manchester. It was funded by the Orchid Charity and The Barts and London Charity.
The study was published in the peer-reviewed medical journal Cancer Causes Control.
The Mail Online gave an accurate reflection of the study and included advice from the male cancer charity Orchid, that men should be more “aware of the warning signs and symptoms of the disease, and that those with worrying symptoms seek medical advice as soon as possible”. It also provided a case study of a man who was embarrassed about his symptoms and even hid them from his wife for a year before seeking medical help.
What kind of research was this?
The researchers wanted to see if the rates were increasing or decreasing, so they could provide information on how services for people with cancer can best provide care and improve outcomes. As this was an epidemiological study using a mixture of cross-sectional and cohort statistics, it can show trends, but does not provide direct evidence for the reasons behind any change.
What did the research involve?
The researchers obtained records of penile cancer cases from the National Health Service Central Register (NHSCR) for 1971 to 2010 and death records from the Office for National Statistics (ONS) for 1979 to 2009.
The researchers excluded cases that:
- had incomplete data
- were benign tumours
- were due to other cancers, such as metastases, lymphoma, leukaemia or myeloma
- were aged at least 100 at the time of diagnosis
- if it wasn't clear from the records whether they were alive on December 31 2011
- only had a death certificate
They then calculated:
- incidence rates (the number of new cases of penile cancer per year from 1979 to 2009. These were “age-standardised” to allow for differences in the population’s age distribution over time)
- prevalence rates (the total number of penile cancer cases from 1995 to 2004)
- mortality (the number of deaths from penile cancer each year from 1979 to 2009)
- survival rates (an estimate of the percentage of people who survived for at least one year and five years after diagnosis).
What were the basic results?
There wer 9,690 men diagnosed with penile cancer in England between 1979 and 2009.
Age-standardised incidence rate increased 20%, from 1.10 to 1.33 per 100,000 men a year – most of this increase has occurred since 2000.
The researchers estimated the 10-year prevalence of penile cancer to stand at 7.6 per 100,000 men. This means that among the patients of a large GP family practice (around 20,000 men and women), there were only likely to be one or two men with penile cancer over a 10-year period.
Age-standardised mortality rates for penile cancer fell by 19% over the 31-year period studied – from 0.38 to 0.31 per 100,000 men. Meanwhile, age-standardised one-year survival increased from 76.2% to 87.1%, and five-year survival increased from 61.4% to 70.2%.
Researchers also found that the chances of survival decreased the higher the age at diagnosis:
- One-year survival was 90% or more; five-year survival was 75% for men diagnosed when they were below 60 years of age (during 2006-2010).
- One-year survival was around 78%; five-year survival was 53% for men diagnosed when they were 80 or older (during 2006-2010).
How did the researchers interpret the results?
The study authors say that the “incidence [of penile cancer] has been increasing, so there is a need for preventative strategies. Public health education about the risks of sexually transmitted diseases, smoking and poor genital hygiene in relation to penile cancer is essential. Another preventative strategy is HPV vaccination of boys”.
The authors also reference the 2009 International Consultation on Urologic Disease Consensus Publishing Group, which “suggests circumcision and early treatment of phimosis (a condition where the foreskin is too tight to be pulled back over the head of the penis), together with significant changes in global health policy”.
This study found that the incidence of penile cancer increased by 20% from 1979 to 2009; however, it fluctuated during the period. For example, the incidence in 2008 was the same as in 1980, although the overall trend is that of an increase. The study does not prove the causes of this increase, but the most important factors known to increase the risk include:
- human papilloma virus (which causes warts)
However, it is also possible that the increased incidence of penile cancer is due simply to more people being diagnosed.
The apparent good news is that the proportion of men surviving for at least a year increased from 76.2% to 87.1%, and five-year survival increased from 61.4% to 70.2%. As the researchers point out, this may have been due to the “advancement of diagnostic, staging and surgical techniques”. However, the interpretation of one-year and five-year survival rates is complex, as it is also possible that penile cancer cases are being diagnosed earlier, leading to a increase in survival time with a diagnosis.
The most encouraging statistic is that the number of deaths due to penile cancer fell by 19% over the period studied.
Being aware of the symptoms of penile cancer, and being willing to discuss these with your doctor might lead to an earlier diagnosis and greater likelihood of successful treatment, including procedures that preserve the penis.
If you have any of the following symptoms, it is advisable to visit your doctor:
- bleeding from the penis
- colour change or rash on the penis
- difficulty pulling the foreskin back over the head of the penis
- smelly discharge
Lumps on the penis are not necessarily a sign of cancer, and there are many benign causes of a lumpy penis.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
Mail Online, 19 February 2014
Links to the science
Cancer Causes and Control. 2013; 24: 2169-2176