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Melanoma and Pregnancy: 'Prompt Biopsy Is Key'


 

SAN DIEGO — Pregnant women who present with changing nevi should not be treated differently from other patients of similar age, Dina R. Massry, M.D., said at a melanoma update sponsored by the Scripps Clinic.

“Prompt biopsy is key,” said Dr. Massry, a dermatologist with the division of dermatology and cutaneous surgery at the Scripps Clinic-Torrey Pines, La Jolla, Calif.

While it is commonly accepted that nevi enlarge and change during pregnancy and that new nevi develop, pregnant women “may get a false sense of security and disregard something that may be potentially worrisome and not get evaluated,” she noted. Pregnant women may not be aware that they should be concerned about irregular or changing moles.

Any changing mole—especially one that has become irregular or asymmetric—could be a melanoma. Synchronous and homogeneous darkening of multiple moles “is probably normal but still should be evaluated,” she said. A delayed diagnosis of melanoma in pregnant patients illustrates that physicians should treat changing nevi exactly the same in pregnant and nonpregnant patients, and biopsy the moles promptly.

No study has identified a difference in survival rates between pregnant patients with melanoma and nonpregnant, age-matched controls, but studies consistently show an increase in median thickness among pregnant patients with melanoma, compared with nonpregnant, age-matched controls. While a delay in melanoma diagnosis is the likely cause for this difference, Dr. Massry said that there are no data to confirm or refute the possible role of growth factors that induce thicker and more rapidly growing melanomas.

In her presentation, she also addressed the following questions related to melanoma:

▸ How does one approach recurrent melanoma in pregnant patients with stage II-IV disease? CT and x-ray can be used if the benefits and risks are discussed with the patient. One study supports the use of MRI in the systemic work-up (Semin. Oncol. 2000; 27:623–32).

Another analysis (Curr. Opin. Oncol. 1999;11:129–31) reports that the manufacturers and suppliers of interferon have “sparse data” on pregnant patients that suggest babies delivered to mothers receiving interferon therapy have low birth weights, Dr. Massry said.

She added that dacarbazine is considered the best treatment for pregnant patients with advanced disease.

▸ What is the risk to the fetus in a pregnancy complicated by melanoma? Transplacental metastases occur only in patients with hematogenous dissemination of melanoma. The incidence of maternal malignancy during pregnancy is 1 per 1,000, and melanoma accounts for 8% of all cancers during pregnancy.

“About 25% of the cancer that is metastatic to the parts of conception involve the fetus,” Dr. Massry said. “Of cases with fetal involvement, 58% or so arise via melanoma.”

At birth, she advised, “you want to do a thorough evaluation of the infant, a gross microscopic examination of the placenta, and [an examination of] the cord blood buffy coat for tumor cells.”

▸ When can a woman safely become pregnant after treatment of melanoma? The commonly accepted advice is to avoid conception for 2–3 years if their lesions were 1.5 mm or smaller and 5–8 years if their lesions were greater than 1.5 mm. Part of this recommendation has to do with [when] most recurrences are likely to occur, she said. “If you're talking to a 20-year-old woman versus maybe a 40-year-old woman, the recommendations may change, depending on what their sense of urgency is” regarding childbearing.”

Some investigators support the notion of individualized recommendations depending on tumor thickness, stage of diagnosis, age of the patient, and the desire of the patient to become pregnant (Cancer 2003;9:2130–3).

▸ Is there a link between melanoma and use of oral contraceptives or hormone therapy? Older studies suggest that high-dose oral contraceptives raise the risk of melanoma, but newer studies that include epidemiologic analysis refute the earlier data. For example, a controlled study of more than 2,000 women found no relationship between the incidence of melanoma and oral contraceptive use, age at onset of use, number of years used, or proximal relationship to use (Br. J. Cancer 2002; 86:1085–92).

Dr. Massry noted that there is “a paucity of information” on hormone therapy and melanoma. Some investigators maintain that there is no reason to withhold hormone therapy from a woman if it is otherwise recommended (Climacteric 2002;5:197–200).

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