Tendency of fluorouracil to conceal deep foci of invasive basal cell carcinoma

Abstract

Topical fluorouracil treatment of invasive basal cell carcinomas (BCC) is not recommended because it often produces the appearance of control with superficial inhibition of the tumor as the deeper extensions continue to grow, which results in a needless delay in obtaining effective treatment. These conclusions are based on data obtained during the microscopically controlled excision of 103 invasive BCCs of the face that had recurred after topical fluorouracil treatment.

Metastatic Basal Cell Carcinoma Presenting as Unilateral Lymphedema

“…We are currently unaware of any other cases of MBCC reported in the literature in which the presumed primary tumor was initially treated with 5‐FU. Mohs et al pointed out in 1978 that 5‐FU may conceal invasive BCC 7 . The question may be raised if long‐term treatment with 5‐FU should be added to the list of risk factors for MBCC.…”

The effect of microneedles on the skin permeability and antitumor activity of topical 5-fluorouracil

“…Unfortunately, the skin permeability of topically applied 5-FU is poor 10–12 , likely due to its hydrophilic nature (Log P =−0.89) 13 . The use of topical 5-FU in BCC therapy is only limited to superficial BCC, and it is not recommended for invasive forms of BCC 4,14 . This is based on a study by Mohs et al 14 , who reported that topical application of 5-FU in invasive BCCs can mislead clinicians by showing superficial improvement, while the deeper parts of the cancerous lesions continue to grow unnoticed.…”

Topical cytostatic drugs in the treatment of skin cancer*

“…He emphasized, however, the need for prolonged treatment times of between 4 and 12 weeks and careful follow-up. Mohs et al (1978) agree that Bowen's disease responds to topical 5-FU therapy but point out that the neoplasm often extend to the bottom of the hair follicle and recurrences may occur because the 5-FU may not reach this area. The effect of 5-FU on Bowen's disease around the perineum and in particular on the multicentric pigmented type, is controversial.…”

“…due to late radiation change or inorganic arsenic or in the basal cell naevus syndrome) appeared to behave differently. A caveat to the use of 5-FU in basal cell carcinoma of the skin has been made by Mohs, Jones & Bloom (1978). They reported 103 patients who had received 5-FU (in most cases when other treatment regimes had failed).…”