Penile cancer: Boys too need the HPV vaccine

As the campaign in support of Human papillomavirus (HPV) vaccination begins to bear fruit in Kenya, a group of mothers in a health talk I was privileged to give wanted to know why Kenya is not offering the vaccines to boys like other countries. 

These mothers were already sold onto the idea, had ensured their daughters had gotten vaccinated with the HPV vaccine and several of them were either taking the vaccine or considering starting the same. The government’s decision-making process with regard to how vaccines are on-boarded onto the national immunisation schedule takes into consideration the evidence base for adoption, acceptability, adaptability, budgets, cost-effectiveness and prioritisation. 

This understanding helped them appreciate the reasons why we are currently offering the vaccine to girls aged 10 to 14 across the country and why parents must support the government initiative by presenting these young ones in a timely manner. The conversation moved on to the benefits of vaccinating the boys and why parents may be compelled to think about paying for the service.

The Human papillomavirus’s most catastrophic effect has been in cervical cancer. However, this is not the only life-threatening condition that this seemingly nondescript virus can result in. The virus presents in over 180 different subtypes, each with a unique affinity for a specific tissue type in the body. These include the cervix, vagina, vulva, penis, anus, skin, mouth, pharynx, larynx, trachea and bronchi. 

The damage initiated by the virus depends on the subtype and the tissue it resides in. This may cause warts, polyps, pre-cancerous lesions and finally full-blown cancers. Hence the virus has been implicated in genital and non-genital warts; laryngeal polyps causing hoarseness of voice; nasal polyps that cause snoring and irritation; non-cancerous penile ulcers; and cancers of the post-nasal space, larynx, cervix, vagina, vulva, anus and yes, penis. 

Penile cancers are fairly uncommon, with about 36,000 new cases being recorded globally in 2020 by the International Agency for Research on Cancer (IARC). The majority of these cancers, as it is mostly the case, tend to occur in the Global South. One in every three afflicted with this will not survive.

Epidemiologic studies report that the highest rates of penile cancer are recorded in South America, with Brazil having the highest numbers, though not the highest prevalence, and Paraguay and St Lucia topping the incidence rate charts; Southern Africa, where Botswana sticks out as a sore thumb in Africa, and Uganda holding the lead for Eastern Africa. Asia is led by Nepal and India. What is worth noting is that with poor health-seeking behaviour and poor diagnosing capacity, the cancer incidence may be under-reported. 

Penile cancer tends to occur more commonly on the prepuce (foreskin) and the glans (head) of the penis. The effects of penile cancer, however, remain extremely devastating as most patients will delay seeking help, and treatment options getting more limited with advancement of the cancer. Generally, men have poorer health-seeking behaviour than women, hence they are more likely to visit a healthcare provider much later. In penile cancer, the patient is even more likely to feel embarrassed to seek care earlier. 

What is even worse is that it may take several visits before the cancer is suspected as penile lesions are more likely to be considered as sexually transmitted infections and treated as such for a long while, as the cancer advances. The rarity of the cancer is one of the reasons why healthcare providers may also lack a high index of suspicion to think of it as a cancer early on. 

And as you may have guessed, HPV infection remains the leading risk factor for getting penile cancer. Other important risk factors include age (more common above the age of 60); phimosis (inability to retract the foreskin covering the glans of the penis); non-circumcision (though circumcision’s greatest protective impact is felt when the circumcision is carried out in the newborn period, not in adulthood); multiple sexual partners; sexually transmitted infections; HIV infection; immunosuppression due to immunosuppressive therapies for organ transplant; psoriasis treatment using psoralen plus ultraviolet A ; smoking and other forms of tobacco use; low socio-economic status; and low level of education. 

Treatment options for penile cancer include surgery, radiation and chemotherapy, with the sole intention of removing the cancerous tissue, all the while preserving as much penile function and appearance as possible. Tumours are diagnosed, staged and classifies as high risk or low risk, and this determines the treatment plan.

For low-risk tumours, treatment aims to spare as much of the penis as possible. It may include topical application of specific medications on the cancer lesion, with or without radiation, surgery and laser treatments. However, these minimal treatments have a higher risk of recurrence of the tumour, hence the need for close continuous monitoring. High risk tumour treatment requires a more aggressive approach of treatment. 

Radiation treatments require large doses of radiation, resulting in complications such as inflammation of the urethra, with scarring and formation of strictures; increased risk of urinary tract infections, blockage of the urethral opening at the head of the penis and resultant fistula formation. 

Laser treatments are suitable for pre-cancerous lesions on the penis before they invade the underlying tissue and turn into full-blown cancer; and very early cancer too. The treatment is non-invasive and the patient recovers quickly with minimal complications and maintenance of sexual function. However, the rate of recurrence is high. 

Surgical treatments are varied, based on the stage of cancer, the depth and the surface area. They may be minimal and non-disfiguring, including circumcision, where the cancer involves the foreskin only; and range all the way to partial or total removal of the penis. What determines how much of the penis comes off is ensuring that the tumour is fully removed, with at least a 5mm margin of penile tissue that is cancer-free. 

Where possible, the urologist aims to preserve at least some penile length to allow for the patient to pass urine while standing up, and hopefully maintain some form of sexual function. Where this is not possible, the entire penis must come out and the urethra is diverted to the perineum and the patient has no option but to sit on the toilet to pass urine. Additionally, surgery also involves dissecting lymph nodes to classify the cancer as advanced or not. Relapses are fairly common and tend to have limited treatments options, resulting in the need for palliation.

It is clear that penile cancer treatment is quite a harrowing experience with huge physical and psychological ramifications for the patient; and it also impacts  personal relations at a deeper level. On this scale, it tends to evenly compare with the impact of cervical cancer on the female. 

The case for prevention of penile cancer is made. What is left is the evaluation of economic benefit of HPV vaccination for a cancer considered to be a lower burden of disease, based on how rare it is. Maybe throwing in the additional benefit of protection against anal cancer and genital warts in men will make sense sooner rather than later!

Dr Bosire is an obstetrician/ gynaecologist