Patients just beginning treatment with different EGFR inhibiting drugs, such as Vectibix or Erbitux, were randomly told to apply sunscreen or a placebo cream twice a day for four weeks. The study was doubled-blinded — neither the patients nor their doctors knew who was getting the real sunscreen.
Doctors monitored the development of skin rash and patients reported on how rash affected their quality of life during the four weeks of sunscreen or placebo and for an additional four weeks after the study ended.
During the time sunscreen was being used and for the following month, there was no difference in occurrence or severity of rash nor in patient-reported quality of life.
During the initial four weeks of the study, 54 patients applied sunscreen with a sun protection factor (SPF) of 60, 56 used a placebo cream.
Doctors found that 38 (78 percent) of the sunscreen-using patients developed a rash during the first four weeks, 39 (80 percent) of those on placebo did. No differences in rates of rash developed over the following four weeks.
While quality of life for all patients declined during the study, there was no difference between the two groups.
Both groups remained similar even when the research team adjusted for geography, season of the year, and for those taking medicines that increased sensitivity to the sun.
The researchers led by Aminah Jatoi at the Mayo Clinic concluded,
Sunscreen, as prescribed in this trial, did not prevent or attenuate EGFR inhibitor–induced rash.
SOURCE: Jatoi et al., The Oncologist, Vol. 15, No. 9, 1016-1022, September 2010
What this Means for Patients
While sunscreen may not make a difference in whether you develop a rash from Erbitux or Vectibix, remember that these biologic agents are often given in combination with chemotherapy.
Both 5-FU and irinotecan, as in the FOLFIRI regimen, make skin more sensitive to the sun. Patients on those drugs are encouraged to avoid sun exposure — wear hats, long-sleeves, and use sunscreen with an SPF of 15 or higher.