RESULTS
Our analysis included 176 patients with NMSC who were treated during the study period; most patients were treated by a single senior surgeon. Of these, 85 (48.4%) were male and 91 (51.6%) were female, with a male-to-female ratio of 0.94:1. The mean age was 70.8 years (range, 29–93 years). The largest group of patients ranged in age from 71–80 years (n=57, 32.6%), followed by those aged >80 years (n=54, 30.7%). The mean tumor size was 1.56 ± 0.95 cm; 149 patients had a tumor <2 cm in size (T1, 84.7%), whereas 26 had a tumor >2 cm in size (T2, 15.3%) (
Table 1).
Basal cell carcinoma (BCC; n=102, 57.9%) was the most common histopathological type, followed by cSCC (n=66, 37.5%) and basosquamous cell carcinoma (n=3, 1.70%). Other histopathological types included microcystic adnexal carcinoma, merkel cell carcinoma, and acinic cell carcinoma of the parotid gland with skin invasion (n=1, 0.56% for each). Six different pathological diagnoses were confirmed, and secondary tumors (i.e., metastatic carcinomas) were diagnosed in 2 patients (1.1%) (
Table 2,
Fig. 2).
NMSCs were treated by complete surgical excision, followed by pathologic determination of tumor-free surgical margins. Skin defects resulting from surgical excision were reconstructed via primary closure in 19 patients (10.8%) or covered using a local flap, full-thickness skin graft, or split-thickness skin graft in 129 (73.3%), 18 (10.3%), and 10 patients (5.7%), respectively (
Table 3). Thirty-one cSCC patients in the high-risk group underwent lymphoscintigraphy according to National Comprehensive Cancer Network guidelines [
7]. Of these, 17 patients (54.8%) with confirmed nodal metastases underwent regional lymph node dissection, and 15 had pathologically positive lymph nodes.
Despite undergoing regional lymph node dissection, 2 patients (11.8%) with similar cases developed recurrent nodal metastases. In one case, the patient presented with an ulcerative cancer on the lower lip, and sentinel node mapping detected positive sentinel nodes in the submandibular area via lymphoscintigraphy. The patient underwent wide excision of the lip, reconstruction with a bilateral fan flap, and regional lymph node dissection from the submandibular area. Pathological reports indicated that the submandibular nodes were negative for cancer invasion. However, the patient developed an enlarged lymph node in the right neck after 16 months (
Fig. 3).
In the other case, the patient presented with recurrent fungating mass on the lower lip, and underwent lymphoscintigraphy, during which injected dye was visualized at the right cervical level I lymph node. The patient underwent wide wedge excision of the lip, reconstruction with a modified Gillies fan flap, regional lymph node dissection, and submandibular lymph node biopsy via gamma probe. Although pathological reports indicated that the lymph nodes were negative for malignancy, 13 months later, the patient developed an enlarged lymph node in the right neck and underwent modified radical neck dissection (
Fig. 4).
Both recurrent cases underwent modified radical neck dissection by an otolaryngologist. Pathological reports indicated ipsilateral lymph node invasion with a safe margin resection. Although further evaluations (e.g., magnetic resonance imaging) have not been performed, these patients have been closely followed under multi-disciplinary consultation (plastic reconstructive surgery, otolaryngology, and hemato-oncology).
DISCUSSION
Skin cancer was recently reported to be the most frequently diagnosed type of cancer [
1], with >2 million cases diagnosed annually worldwide [
10]. However, skin cancer accounts for only 4% of reported malignancies in Korea, suggesting that the related statistical data are inadequate. Nevertheless, the incidence of skin cancer is increasing steadily, presumably due to changing lifestyles as well as increased exposure to ultraviolet rays, radiation, and chemical pollution; medication use; an aging population; and other environmental factors. Therefore, this disease and its diagnosis and treatment warrant additional attention [
1].
BCC is the most common type of skin cancer, accounting for approximately 80% of reported cases [
11,
12]. However, BCC accounted for only 50.2% of cases at our institution. Although BCC rarely spreads to the lymph nodes or distant organs, it can invade locally and destroy neighboring tissues [
13]. The most frequently affected sites include sun-exposed areas such as the face, which is subdivided into the perioral and nasal regions, upper lip, and helical portion of the ear [
11]. However, BCCs have also been detected on covered areas of skin (e.g., the upper arm, chest, and thigh [
13]). Treatment for this rarely metastatic cancer usually involves complete surgical excision and restoration; for the latter, the local flap method is optimal because it preserves the tissue color and texture. Skin grafts are also a useful method of restoration, although they result in a poorer aesthetic appearance and are therefore usually the last-choice method. In addition, electric desiccation, cryotherapy, 5-fluorouracil, or Mohs surgery may be used for early-stage BCC [
3,
11]. In our experience, BCCs were treated according to National Comprehensive Cancer Network guidelines [
2], and 1 case of local recurrence was treated successfully by re-excision with no instance of metastasis.
cSCC is the second most common type of skin cancer, accounting for 15%–20% of reported cases [
9,
14]. These cancers are usually observed on sun-exposed areas such as the cheek, lower lip, perioral region, and forehead, although rarer types may arise from chronic ulcers, burns, or injuries [
1,
8]. The incidence of nodal metastasis varies, ranging from 10%–12% for cSCCs of the face and neck and 15%–20% for those arising from a chronic ulcer (Marjolin's ulcer), the lip, or around a fistula [
15]. Distant metastasis with lymph node involvement can be fatal [
3,
5,
8,
9]. Therefore, nodal metastasis investigation requires special attention [
7].
In our study, we performed both sentinel node mapping [
5,
16] and regional lymph node dissection [
16,17]. Despite our efforts, however, 1 of 66 patients eventually developed metastases. Patients with cSCC tumors >2 cm in size with ulceration, locations surrounding fistulae, and anatomically prone locations (e.g., head and neck region cervical lymph nodes) underwent sentinel node mapping. Other malignancies, such as microcystic adnexal carcinoma, merkel cell carcinoma, and acinic cell carcinoma, were treated via complete excision with tumor-free surgical margins and follow-up. However, our sample included very few of these cases, and therefore we are unable to draw conclusions about these tumor types.
One patient with BCC of the right orbit had been treated at another institution. The disease recurred after incomplete excision, and the patient subsequently underwent radiation therapy, leading to radiation necrosis of the orbital area and subsequent blindness and necrosis of the entire right orbital region. This patient later developed SCC that eventually metastasized to the lymph nodes and lungs (
Fig. 5).
As mentioned above, we experienced rarer, atypical forms of NMSC, including a case of acinic cell cancer of the parotid gland that penetrated through the skin. Although the mortality rate of NMSC is low, initial proper treatment is essential, regardless of cancer type. NMSC treatments were administered according to our institutional algorithm (
Fig. 6).
In particular, the surgical application considered traditional and optimal comprised complete excision and reconstruction with a local flap to preserve the facial skin color, texture, and contour.
Although our report describes a significant investigation based on a regional experience with skin cancers treated by a single senior surgeon, we lack evidence with which to conduct a statistically significant analysis and draw conclusions regarding skin cancer treatment. It will also be necessary to evaluate the prognosis of high-risk skin cancers in a follow-up study. In future studies, we plan to identify and analyze diagnoses, treatments, and follow-up findings of high-risk cSCC patients.
In conclusion, skin cancer is presently the most common type of cancer in humans, and its incidence continues to increase. However, epidemiologic and diagnostic studies remain inadequate. Early diagnosis and appropriate treatment represent essential steps toward reducing the associated morbidity and mortality rates. In our experience, although BCCs are rarely metastatic, complete excision with tumor-free surgical margins and restoration with a local flap comprise the most effective surgical treatment. In contrast, cSCCs can cause nodal metastases that lead to devastating deformities and even death, and therefore require further nodal evaluation (e.g., lymphoscintigraphy).