[Surgery and additional protontherapy for treatment of invasive and recurrent squamous cell carcinomas: technique and...

Invasive squamous cell carcinomas are uncommon neoplasias with high recurrence and mortality rates. The improvement of tumoral control requires additional treatments such as cryotherapy, topical chemotherapy, and radiotherapy. We present the technique and preliminary results of associating treatment with surgery and proton beam therapy for recurrent and invasive squamous cell carcinomas.

From June 2001 to September 2008, 15 patients were treated in our ocular oncologic center for squamous cell carcinomas either with recurrences or with invaded resection margins. The treatment combined new surgical resection with protontherapy. Specific improvements in proton beam therapy have been made at the Nice Cyclotron to adapt the treatment to conjunctival tumors. Proton beam carving consists in using a specific device to treat the thickness of the whole lesion site and the adjacent conjunctiva and to spare the surrounding healthy structures.

Patients were staged according to the TNM classification of malignant tumors in T2: 3; T3: 5; T4: 7. Mean follow-up was 39.1 months (range, 6-90 months). Our 15 patients included 12 males and three females. Left eyes were involved in eight cases. The mean age at first consultation was 63.7 years (range, 46-80 years). In 13 cases (86.8%), the bulbar and limbic conjunctiva was involved, in five of these cases the cornea was invaded, and the anterior chamber was involved in one case. In one case, the tumor was located on bulbar conjunctiva near the caruncle (6.6%) and in one case in the fornix (6.6%). One patient died of another cancer after 48 months of follow-up. We obtained local tumor control for 13 patients (86.8%) and recurrences for two patients (13.2%). One of them has presented with cervical node metastases. These two patients who presented recurring and extensive tumors had had previous repeated surgeries in other centers. Moreover, proton beam therapy was performed more than 6 months after the initial treatment. Exenteration and enucleation had to be performed to treat these recurrences 6 and 24 months after proton beam therapy. The exentered patient has been lost to follow-up. No patients developed recurrences with additional proton beam therapy performed within 6 months after initial surgical resection. As for side effects, seven patients suffered from sicca syndrome, six needed cataract surgeries, three unesthetic dilatations of episclera vessels, two conjunctival postradiation dysplasias, two experienced eyelash loss, one stenosis of the lacrimal duct, and one glaucoma controlled by monotherapy. Conjunctiva and amniotic grafts had to be performed on one of the patients presenting with dysplasia. Due to the rarity and diversity of these cases, it is nearly impossible to carry out prospective and comparative studies.

Traditional adjuvant treatments often failed to control recurring and invasive squamous cell carcinomas. We often ended up performing exenteration to control local recurrences. The preliminary results of the present study suggest that proton beam therapy may be considered as a good alternative to traditional treatments with acceptable side effects.