Invasive squamous cell carcinoma
Pro Research Analysisby 
Searched over 200M research papers
Invasive Squamous Cell Carcinoma: An Overview
Epidemiology and Risk Factors
Invasive squamous cell carcinoma (SCC) is a prevalent form of skin cancer, particularly among white populations, accounting for approximately 20% of all cutaneous malignancies. Key risk factors for cutaneous SCC (cSCC) include prolonged exposure to ultraviolet (UV) radiation, chronic photoaging, advanced age, male sex, immunosuppression, smoking, and genetic predispositions. Similarly, invasive squamous cell carcinoma of the cervix shares common risk factors such as multiple sexual partners, early age at first intercourse, high parity, and prolonged use of oral contraceptives.
Pathogenesis and Progression
The progression of cSCC often begins with actinic keratosis (AK), a precancerous lesion caused by UV damage. AK can evolve into invasive SCC, particularly when atypical basal cells are present. The risk of progression from AK to invasive cSCC varies depending on the severity of the AK, with severe cases (Olsen grade III) showing a significantly higher risk.
Diagnosis and Staging
Diagnosis of cSCC involves a thorough physical examination, including total body skin checks and palpation of lymph nodes. High-risk cases may require radiologic imaging such as ultrasound, MRI, CT, or PET-CT scans for accurate staging. Staging systems like the American Joint Committee on Cancer (AJCC) 8th edition and the Brigham and Women's Hospital (BWH) system are commonly used to classify the extent of the disease.
Clinical Features and Prognosis
Clinically, cSCC can resemble basal cell carcinoma (BCC) but tends to be more aggressive with a higher metastatic potential. Common cSCCs generally have a favorable prognosis with a 5-year cure rate exceeding 90% and a metastasis rate of less than 4%. However, poorly differentiated tumors, large tumor size, and regional nodal involvement significantly increase the risk of recurrence and mortality.
Treatment Options
Surgical Treatments
Surgical excision remains the primary treatment for invasive cSCC, offering high cure rates when complete removal with margin control is achieved. For high-risk patients, adjuvant therapies may be considered to reduce the likelihood of recurrence.
Nonsurgical Treatments
Nonsurgical options include topical treatments like 5-fluorouracil and imiquimod, photodynamic therapy, and cryotherapy. These methods are particularly useful for patients who are not ideal candidates for surgery due to age or comorbidities. However, the efficacy of these treatments varies, and further studies are needed to establish optimal protocols.
Prevention and Chemoprevention
Preventive measures against cSCC emphasize sun protection, including the use of sunscreens, protective clothing, and avoiding artificial tanning. Chemopreventive agents like nicotinamide and oral retinoids have shown some promise in high-risk patients but are not routinely recommended.
Conclusion
Invasive squamous cell carcinoma is a significant health concern with various risk factors and clinical presentations. Early diagnosis and appropriate treatment are crucial for favorable outcomes. While surgical excision remains the gold standard, nonsurgical treatments offer viable alternatives for certain patient populations. Preventive strategies and ongoing research into chemoprevention are essential to reduce the incidence and improve the management of this aggressive cancer.
Sources and full results
Most relevant research papers on this topic