Is Lichen Sclerosus Cancerous?
Malignant potential of lichen sclerosus (LS) has been debated for decades and there is no proper theory whether it actually causes malignancy and if so, how. However, LS is identified as a precancerous lesion by many doctors now. Especially, the LS that affect the vulva and the penis has a tendency to turn into malignancy.
The risk of vulval lichen sclerosus turning into cancer of the vulva is about 4 to 5%. The risk of getting penile cancer is less than that, but the exact figure is not known.
The Risk Factors For Malignancy:
- Ulcerative lesions of lichen sclerosus.
- Corticosteroid therapy.
- Genetic predisposition.
- Age – elderly females and males are at more risk.
- Immune status.
There are some studies done on females and males with lichen sclerosus and the risk of getting vulval cancer, penile cancer and other cancers.
A study done from 1970 to 2014 on 7,600 females with LS with a mean follow-up 8.8 years showed that there is an increased risk of vulvar squamous cell carcinoma (VSCC) among these patients. The risk is about 5% in patient who have vulval lichen sclerosis. A 10% of patients in the study developed vulval carcinoma. Most of these patient got vulval squamous cell carcinoma. The risk of vulval carcinoma was especially high during the first year of follow-up. These patients sought medical advice due to the symptoms of cancer. However, the risk of vulvar cancer among patients with LS remained elevated through the whole follow-up period, suggesting a true association. The risk was highest among women over 80 years 460/100,000 person-years.
Another study done from 1991 to 2011 on 3038 women with LS showed the incidence rate of LS increased from 7.4 to 14.6 per 100,000 woman-years. The median age at time of LS diagnosis was 59.8 years and the incidence of VSCC was 6.7%. The 10-year VSCC incidence in women with LS was associated with concurrent vulvar intraepithelial neoplasia (VIN is a premalignant lesion) and age at time of lichen sclerosus was diagnosed.
The results are from the same study. There is also an increased risk of getting vaginal cancer, this was unusual as lichen sclerosus does not usually cause vaginal cancer. However there were about 4 cases in the study with vaginal cancer.
The risk of getting cervical cancer was reduced in the study. This can be due to the fact that these patient have an impaired sexual life because of LS affecting the normal anatomy of the vulva. So, these patients are less exposed to human papilloma virus, which is the common cause of cervical cancer. Also since LS can be precipitated by smoking these patients are not smokers which is also another risk factor for cervical cancer.
Other extra genital lesions were not found to be associated with malignant transformation in this study.
Studies have shown that men with lichen sclerosus are at increased risk of getting penile cancer. The risk is about 2 to 12.5%.
One study done on 86 men with penile LS from 1987 to 1997 showed five cases of malignant transformation to squamous cell carcinoma (SCC). From these five cases, three cases were SCC, one case of in situ carcinoma/Queyrat’s erythroplasia and one case of verrucous carcinoma. In situ carcinoma and verrucous carcinoma are also SCC, which only affects the top layers of the skin. The glans penis was the common site to get affected. The average onset of LS was 45 years and the development of cancer was at 62 years. Lag period is about 18 years.
Another study done on 130 male patient with LS showed 11 men with premalignant or malignant penile cancer. Out of that 7 cases were squamous cell carcinoma, 2 cases were verrucous carcinoma, one case with both SCC, verrucous type and the one case of carcinoma in situ. The time interval between diagnosis of LS and development of SCC was 14 to 30 years.
Lichen sclerosus has an increased risk of turning into malignancy over the years. The main types of malignancy seen are vulval cancer, vaginal cancer in females and penile cancer in males. The risk of developing vulval cancer in females with lichen sclerosus is about 2% and the risk of penile cancer risk is about 2 to 12.5%. Many studies done over the years have shown the above mentioned figures. The risk factors for the development of carcinoma include the ulcerative lichen sclerosus, genetic predisposition, increase age, smoking and corticosteroid therapy.