Two hundred fifty-four patients receiving postoperative radiation therapy for breast cancer were randomly assigned, in single-blind fashion, to apply topically either trolamine (triethanolamine salicylate; considered by many to be the treatment of choice) or Calendula officinalis (Pommade au Calendula par Digestion; Boiron Ltd, Levallois-Perret, France) ointment on the irradiated fields after each session. Treatment was begun after the first radiation session and was applied twice a day or more, depending on the occurrence of dermatitis and pain. The incidence of acute dermatitis of grade 2 or higher was significantly lower (41% v 63%; p < 0.001) with calendula than with trolamine. Compared with trolamine, calendula was associated with fewer interruptions of radiotherapy because of skin toxicity (0 vs. 12 patients) and significantly less radiation-induced pain (p = 0.03). Calendula was more difficult to apply, but overall satisfaction with its use was greater than with trolamine.

Comment: Acute dermatitis is a common side effect of radiation therapy. Calendula is a common garden plant in North America and Europe. Its flowers have been used traditionally as a topical soothing agent, to treat minor burns and eczema and to promote wound healing. The results of the present study indicate that topical Calendula officinalis is effective for the prevention of acute dermatitis in patients undergoing postoperative irradiation for breast cancer.

Pommier P, et al. Phase III randomized trial of Calendula officinalis compared with trolamine for the prevention of acute dermatitis during irradiation for breast cancer. J Clin Oncol 2004;22:1447-1453.