The most current theories suggest that oxidative DNA damage is generated during normal metabolism in the central nervous system, and that some types of this damage must be repaired by NER.Since DNA repair is under genetic control, it can mutate. Many genetic disorders such as xeroderma pigmentosum (XP; MIM 278700) are caused by mutations in genes that repair damaged DNA. XP affects the mechanism that repairs UV damage in skin cell DNA. Those affected with the autosomal recessive disorder XP are extremely sensitive to UV light produced by the sun and develop pigmented spots, tumors, and skin cancer with minimal exposure. Individuals with XP are about 1,000 times more likely to develop skin cancer than individuals without the disorder.The molecular defects in XP cells result in a greatly elevated induction of mutations in sun-exposed skin of affected individuals. This increased mutation frequency probably accounts for the pigmentation changes and the skin cancers. Examination of mutations in the p53 gene in tumors from XP patients reveal p53 mutations characteristic of UV exposure in the majority of tumors As with all genetic disorders, genetic counseling and psychological support is appropriate for the families to discuss probability of occurrence in future pregnancies, feelings of isolation and concern about career prospects. There is no cure for xeroderma pigmentosum. The most common fate for individuals with XP is early death from cancer.
As with many other stromal neoplasms, DFSPs appear to express low levels of hormone receptors, which may be one factor that accounts for their accelerated growth during pregnancy. Treatment
Treatment is primarily surgical, with chemotherapy and radiation therapy used if clear resection margins are not acquired. Surgical treatment
The type of surgical treatment chosen is dependent on the location of the DFSP occurrence and possible size. Mohs surgery
Mohs Micrographic Surgery (MMS) has a high cure rate and lowers the recurrence reduction of DFSP if negative resection margins are achieved. Wide local excision
WLE was the gold standard for treating DFSP but is currently under reevaluation. Presently in the United States, WLE may be suggested after the recurrence of MMS. Larger resection margins are suggested for WLE than MMS. Recurrence rate with WLE is about 8.5% with a lower recurrence rate related to wider excision. Resection margin
DFSP characteristic features are its capacity to invade surrounding tissues, to a considerable distance from the central focus of the tumor in a "tentacle-like" fashion. This fact, coupled with diagnostic delay, may lead to inadequate initial resection. Inadequate initial treatment results in larger, deeper recurrent lesions, but these can be managed by appropriate wide excision. Radiation therapy
DFSP is a radioresponsive tumor, radiation therapy (RT) is not used as the first choice for treatment. Conservative resection through MMS or WLE is attempted first. If clear margins are not achieved RT, or Chemotherapy is recommended. Chemotherapy
DFSP was previously regarded and nonresponsive to standard chemotherapy.