From the Guidelines
Skin cancer relapse does not always start from the original site. While local recurrence at or near the original tumor site is a possibility, skin cancer can also return in different areas through a process called metastasis, where cancer cells spread through the bloodstream or lymphatic system to distant parts of the body. According to a study published in the Mayo Clinic Proceedings 1, local recurrence is an uncommon event and is most likely a manifestation of residual microsatellites in the neighboring tissue left behind after resection. The study suggests that local recurrences are, in fact, a manifestation of intralymphatic disease, rather than residual primary melanoma cells that grow back with an unusually aggressive biological capacity for metastases.
Some key points to consider when evaluating the risk of skin cancer relapse include:
- The type of skin cancer: melanoma is more likely to metastasize than basal cell carcinoma
- The stage at initial diagnosis
- The depth of the original tumor
- How completely it was removed during treatment
- The risk of recurrence is highest in the first few years after treatment but can persist for many years, making long-term surveillance important, as noted in the study 1.
Regular full-body skin examinations are crucial after skin cancer treatment, as new lesions may develop in previously unaffected areas. Common sites of distant recurrence for melanoma include lymph nodes, lungs, liver, brain, and bone, while basal and squamous cell carcinomas typically recur locally but can occasionally spread to nearby lymph nodes or distant organs.
From the Research
Skin Cancer Relapse
- Skin cancer relapse does not always start from the original site, as evidenced by the various patterns of recurrence observed in studies 2, 3.
- According to a study on melanoma patients, nearly half of the primary recurrences were locoregional metastasis alone, followed by mixed locoregional and distant metastases, and distant metastases alone 2.
- The study also found that the lung was the most frequently affected site for distant metastasis, followed by bone, liver, and brain 2.
- In the case of basal cell carcinoma, the relapse rate was found to be highest for tumors located on the scalp, and treatment methods such as radiotherapy and surgical excision had lower relapse rates compared to curettage and photodynamic therapy 3.
- The definition of skin cancer recurrence is variable and nonstandardized, which can lead to inconsistent management of tumors of uncertain recurrence status 4.
Patterns of Recurrence
- Locoregional relapse alone was associated with a favorable prognosis for outcome in melanoma patients 2.
- Distant metastases were found to occur in approximately 23.5% of melanoma patients, with the lung being the most common site 2.
- Basal cell carcinoma recurrences were found to have a higher relapse rate than primary lesions, and patients with chronic skin diseases had a lower risk of relapse 3.
Factors Affecting Recurrence
- Tumor localization, T-stage, and method of treatment were significant predictors of the risk of recurrence in basal cell carcinoma patients 3.
- Immunocompromise can increase the risk of nonmelanoma skin cancers, including basal cell carcinoma and squamous cell carcinoma 5.
- Fair skin and chronic ultraviolet B exposure are the most important risk factors for skin cancer 6.