A phase II/III clinical study of tin ethyl etiopurpurin (Purlytin)-induced photodynamic therapy for the treatment of recurrent cutaneous metastatic breast cancer.

Background: Chest wall recurrence of breast cancer after mastectomy, radiation therapy, and chemotherapy poses a therapeutic dilemma. Further intervention with any or all of these modalities is often futile and morbid. Left untreated, severe pain, infection, and suffering occur.

Objective: To ascertain whether photodynamic therapy may present a palliative option for these individuals.

Methods: A total of 86 lesions (2.4-cm mean diameter) were treated on eight patients who had biopsy-proven chest wall recurrence despite surgery, chemotherapy, and radiation therapy. Each patient underwent a single photodynamic therapy session in which 1.2 mg/kg of the drug tin ethyl etiopurpurin (Purlytin) was injected and followed 24 hours later by laser light treatment at 660 +/- 3 nm (at 150 mW/cm2 for a total light dose of 200 J/cm2).

Results: With a minimum 6-month follow-up, the objective response rates after photodynamic therapy were complete response, 92%; partial response, 8%; and no response, 0%. Lesions less than 0.5 cm had a 100% complete response. Morbidity was minimal with no systemic toxicity. One patient had a wound infection that responded to oral antibiotics. No photosensitivity reactions were reported in this set of patients. Posttreatment pain was reported and could be treated with medication and application of cold compresses.

Conclusions: Photodynamic therapy offers an excellent local control rate of chest wall recurrence with minimal morbidity after multimodality treatment failure. The treatment is given in a single session and on an outpatient basis. In patients who may register a partial response or have recurrence or the incidence of further chest wall nodules after photodynamic therapy, the treatment is repeatable.