Trisomy 6 in basal cell carcinomas correlates with metastatic potential: a dual color fluorescence in situ hybridization study on paraffin sections

Metastatic basal cell carcinoma: prognosis dependent on anatomic site and spread of disease

PURPOSE

This review provides a description of the epidemiology and survival outcomes for cases with metastatic basal cell carcinoma (mBCC) based on published reports (1981-2011).

METHODS

A literature search (MEDLINE via PubMed) was conducted for mBCC case reports published in English: 1981-2011. There were 172 cases that met the following criteria: primary BCC located on skin, metastasis confirmed by pathology and metastasis not resulting from direct tumour spread. From these, 100 mBCC cases with explicit information on follow-up time were selected for analysis. Survival analysis was conducted using Kaplan-Meier methods.

RESULTS

Among 100 mBCC cases selected for analysis, including one case with Gorlin syndrome, 50% had regional metastases (RM) and 50% had distant metastases (DM). Cases with DM were younger at mBCC diagnosis (mean age, 58.0 versus 66.3 years for RM; P=0.0013). Among 93 (of 100) cases with treatment information for metastatic disease, more DM cases received chemotherapy (36.2% versus 6.5% for RM), but more RM cases underwent surgery (87.0% versus 40.4% for DM). Among all 100 cases, median survival after mBCC diagnosis was 54 months (95% confidence interval (CI), 24-72), with shorter survival in DM (24 months; 95% CI, 12-35) versus RM cases (87 months; 95% CI, 63-not evaluable).

CONCLUSION

Cases with RM and DM mBCC may have different clinical courses and outcomes. Based on published reports, DM cases were younger at mBCC diagnosis, with shorter median survival than RM cases. This study provides a historical context for emerging mBCC treatments.

Metastatic Basal cell carcinoma: a biological continuum of Basal cell carcinoma?

Basal cell carcinoma (BCC) accounts for 80% of all nonmelanoma skin cancers. Its metastasis is extremely rare, ranging between 0.0028 and 0.55 of all BCC cases. The usual metastasis to lymph nodes, lungs, bones, or skin is from the primary tumor situated in the head and neck region in nearly 85% cases. A 69-year-old male developed progressively increasing multiple, fleshy, indurated, and at places pigmented noduloulcerative plaques over back, chest, and left axillary area 4 years after wide surgical excision of a pathologically diagnosed basal cell carcinoma. The recurrence was diagnosed as infiltrative BCC and found metastasizing to skin, soft tissue and muscles, and pretracheal and axillary lymph nodes. Three cycles of chemotherapy comprising intravenous cisplatin (50 mg) and 5-florouracil (5-FU, 750 mg) on 2 consecutive days and repeated at every 21 days were effective. As it remains unclear whether metastatic BCC is itself a separate subset of basal cell carcinoma, we feel that early BCC localized at any site perhaps constitutes a biological continuum that may ultimately manifest with metastasis in some individuals and should be evaluated as such. Long-standing BCC is itself potentially at risk of recurrence/dissemination; it is imperative to diagnose and appropriately treat all BCC lesions at the earliest.

Epidemiology of basal cell carcinoma

Basal cell carcinoma is the most common malignant neoplasm in humans and its incidence has increased over the last decades. Its high frequency significantly burdens the health system, making the disease a public health issue. Despite the low mortality rates and the rare occurrence of metastases, the tumor may be locally invasive and relapse after treatment, causing significant morbidity. Exposure to ultraviolet radiation is the main environmental risk factor associated with its cause. However, other elements of risk are described, such as light skin phototypes, advanced age, family history of skin carcinoma, light eyes and blond hair, freckles in childhood and immunosuppression. Behavioral aspects such as occupational sun exposure, rural labor and sunburns at a young age also play a role. Between 30% and 75% of the sporadic cases are associated with patched hedgehog gene mutation, but other genetic changes are also described. The tumor is commonly found in concomitance with skin lesions related to chronic sun exposure, such as actinic keratoses, solar lentigines and facial telangiectasia. The prevention of basal cell carcinoma is based on the knowledge of risk factors, early diagnosis and treatment, as well as on the adoption of specific measures, particularly in susceptible populations. The authors present a review of the epidemiology of basal cell carcinoma.

Neurocognitive functioning of a child with partial trisomy 6 and monosomy 21

This case study describes the neurocognitive presentation of a child with identified genetic abnormalities of trisomy 6 and monosomy 21 who was evaluated as part of a standard medical protocol for cochlear implantation following diagnosis of profound sensorineural hearing loss. This child received neurocognitive testing prior to cochlear implantation and approximately 12 months post-activation of his cochlear implant. While he has not fully developed oral language, his presentation suggested improvement in overall skills since the activation of the cochlear implant; however, less than would be expected for a typically developing child.

Metastatic basal cell carcinoma: complete response to chemotherapy and associated pure red cell aplasia

Basal cell carcinoma (BCC) is usually a benign and indolent cancer cured in greater than 95 percent of cases. Nevertheless, it can be locally destructive or occasionally metastasize to distant organs. We report a case of BCC metastatic to the lungs, occurring 17 years after the primary BCC was noticed, that responded to carboplatin and paclitaxel on 3 occasions. The patient also developed pure red cell aplasia (PRCA). Work-up did not reveal underlying thymoma or infectious, rheumatologic, or lymphoproliferative disorders. Parvovirus serologies were negative, and antibodies against erythropoetin were not detected. There was no history of exposure to drugs associated with PRCA. Bone marrow biopsy on 2 different occasions did not show evidence of myelodysplasia. PRCA may represent an unusual paraneoplastic syndrome associated with BCC as reported with other carcinomas. This is the first report of PRCA associated with metastatic BCC or the drugs carboplatin and paclitaxel, which were used to treat it. The literature on chemotherapy for metastatic BCC is reviewed.

Repetitive DNA alterations in human skin cancers

Repetitive sequences constitute landmarks for genome regulation, evolution, and chromatin architecture. Patterns of specific and non-specific repetitive sequences change in many types and stages of tumor cells, characterized by band loss, gain, and (de) increased staining of pre-existing bands. In this work, repetitive DNA was studied in search of genome instability of skin cancers: basal and squamous cell carcinomas (BCC and SCC), malignant melanoma (MM), melanocytic nevus (MN), and actinic keratosis (AK) lesions. DNAs were extracted from blood and tumor samples from 21 BCC, 7 SCC, 11 MM and 7 lesions. Banding patterns were obtained by random amplification of polymorphic DNA (RAPD), and specific D9S50 and D9S52 microsatellites (9p21). D9S50 patterns revealed microsatellite instability (MSI) and/or loss of heterozygosity (LOH) in 36% BCC, 25% SCC, and 57% MM tumors. D9S52 microsatellite showed 28.5%; 42.8%; and 71.4% altered tumors, respectively. No microsatellite alterations were found in MN and AK. On the other hand, genomic rearrangements detected by RAPD were present in 100% tumors. In BCC, the mean number of tumor DNA alterations showed predominant gain of bands. On the contrary, MM samples presented loss, or decreased intensity signal of RAPD bands. Genome alterations in skin cancers would result from chromosomal rearrangements, aneuploidy and/or polysomies. The low-cost and quick RAPD technique may reveal unknown genes or DNA sequences associated with tumor development and progression, and may be easily implemented in clinical diagnosis.

Outcome of prenatally diagnosed trisomy 6 mosaicism

We report the prenatal diagnosis of trisomy 6 mosaicism via amniocentesis, in which trisomy 6 cells were identified in three of five culture vessels with 33% (5/15) of colonies showing trisomic cells. The pregnancy was electively terminated and examination revealed minor abnormalities (shortening of the femurs, micrognathia, posterior malrotation of the ears, and bilateral camptomelia of the second digit of the hands and fifth digits of the feet). Cytogenetic analysis of the placenta showed trisomy 6 in 100% of 20 cells studied. Karyotype was 46,XX in 100 cells examined from fetal skin. There are relatively few prenatally diagnosed cases of mosaic trisomy 6 at amniocentesis. Confined placental mosaicism (CPM) has been postulated in other cases where follow-up cytogenetic studies were not available. The present case differs from those previously reported, as it appears to represent CPM of chromosome 6 with phenotypic effects to the fetus.