Effectiveness and toxicity of cetuximab with concurrent RT in locally advanced cutaneous squamous cell skin cancer: a case series

BACKGROUND

Treatment for locally advanced cutaneous squamous cell cancers (laCSCC) remains poorly defined. Most laCSCC tumors express high levels of epidermal growth factor receptors (EGFR). Cetuximab has activity in other EGFR expressing cancers and enhances the effectiveness of radiotherapy.

METHODS

A retrospective review of institutional data identified eighteen patients with laCSCC treated with cetuximab induction and concurrent radiotherapy. The loading dose of cetuximab was 400 mg/m² IV. Subsequent weekly doses of 250 mg/m² IV were infused throughout the period of radiation. The treatment doses ranged from 4500-7000 cGy, with a dose fraction of 200-250 cGy.

RESULTS

The objective response rate was 83.2% with 55.5% complete responses and 27.7% partial responses. Median progression-free survival was 21.6 months. Progression-free survival was 61% at 1 year and 40% at 2 years. With longer follow-up, some patients developed a local recurrence (16.7%), distant metastases (11.1%) or a second primary cancer (16.3%). Cetuximab was well tolerated, with 68.4% patients experienced only mild acneiform skin rash or fatigue (Grade 1 or 2). Radiotherapy produced expected side effects (skin erythema, moist desquamation, mucositis).

DISCUSSION

Cetuximab plus radiotherapy represents an active and tolerable treatment option for laCSCC, including patients with contraindications for checkpoint inhibitor therapy.

Hedgehog Inhibitor Induction with Addition of Concurrent Superficial Radiotherapy in Patients with Locally Advanced Basal Cell Carcinoma: A Case Series

BACKGROUND

Locally advanced basal cell cancer is a rare and challenging clinical problem. Historically, these patients were treated with aggressive surgery or radiotherapy. Most sporadic basal cell carcinomas have somatic mutations in the hedgehog pathway. Oral hedgehog inhibitors induce rapid and often complete clinical responses in locally advanced basal cell tumors. Unfortunately, these responses are usually transient. We hypothesized that treatment failure represents persistence of drug resistant cells that could be eradicated by addition of localized radiotherapy.

MATERIALS AND METHODS

We performed a retrospective review of our patients with locally advanced basal cell cancer treated with sonidegib or vismodegib induction therapy who were treated with added superficial radiotherapy at the time of maximal response.

RESULTS

Twelve patients met inclusion criteria. All patients achieved a complete response following hedgehog inhibitor therapy with addition of radiotherapy. Progression-free survival at 40 months was 89%, with a median follow-up of 40 months. Relapses occurred in only 2 of 12 patients (16.6%). Nine patients experienced grade I-II toxicity from hedgehog inhibitor induction therapy (taste changes [3], weight loss [3], muscle cramps [3]). Eight patients experienced mild radiotherapy-induced skin toxicity during concurrent therapy. No patients had to discontinue treatment.

CONCLUSION

Induction therapy with hedgehog inhibitors followed by addition of concurrent radiation therapy resulted in an extremely high clinical response rate with relatively minor and reversible toxicity. This gave a high rate of progression-free survival and a low disease-specific progression rate. Further prospective evaluation of this treatment approach is needed to confirm the apparent clinical activity.

IMPLICATIONS FOR PRACTICE

Locally advanced basal cell cancers are challenging to treat. Previously, aggressive surgical resection or radiotherapy represented the best treatment options. Most basal cell cancers have somatic mutations in the hedgehog pathway. Oral inhibitors of this pathway produce rapid but transient clinical responses. This study reports 12 patients treated with hedgehog inhibitor induction therapy to near-maximal response. Addition of concurrent involved field radiotherapy resulted in a very high complete response rate with minimal toxicity. There was prolonged progression-free survival in 90% of patients. This study identified a novel treatment approach for patients with advanced basal cell carcinoma.

Palliation of advanced pelvic malignant disease with large fraction pelvic radiation and misonidazole: final report of RTOG phase I/II study

Between October 1979 and June 1982 forty-six patients were entered on a non-randomized Phase I-II protocol for the evaluation of Misonidazole combined with high dose per fraction radiation for the treatment of advanced pelvic malignancies. Pelvic radiation consisted of 1000 cGy in one fraction repeated at 4-week intervals for a total of three treatments. Oral Misonidazole at a dose of 4 gm/m2 was administered 4-6 hr prior to radiation (total dose 12 g/m2). The distribution of histology consisted of 20 gynecologic, 24 bowel, and 2 prostate malignancies. Of the thirty-seven patients completing the three treatments; there were 6 complete responses (14% CR), 10 partial responses (27% PR) 19 minimal or no response (32% NR), and 4 unevaluable. One patient remains NED 5.5 years following radiation. Toxicity directly related to Misonidazole was minimal and consisted primarily of transcient Grade 1, 2 peripheral neuropathy (20% Grade 1, 4% Grade 2) and Grade 2 ototoxicity (4%). Radiation toxicity was significant for late bowel damage. There were 4 (11%) Grade 3 and 7 (19%) Grade 4 gastro-intestinal (GI) toxicities. Kaplan-Meier plot of GI toxicity showed a progressive increase in incidence with time for projected rate of 49% Grade 3, 4 by 12-month. GI toxicity (Grade 3, 4) was also related to tumor response. The complication rate was 80% (4/6) for CR, 30% (3/10) for PR and 26% (5/19) for NR or progression. Because of the GI complication rate, this protocol for palliation of advanced pelvic malignancies has been replaced by a protocol that uses 4 fractions over 2 days (b.i.d.) of 370 cGy per fraction repeated at 3-week intervals for a total of 3 courses.

Enhancement by misonidazole of metastatic tumor nodule formation in the lungs of mice

Investigations were performed to determine whether misonidazole, a hypoxic cell radiosensitizer, influences formation of tumor nodules in the lung of C3Hf/Kam mice and whether it affects the enhancement of tumor nodule formation caused by local thoracic irradiation (LTI). Cells from a chemically-induced fibrosarcoma (FSa) and a spontaneously-developed fibrosarcoma (NFSa) formed twice as many tumor colonies in the lungs of mice that received misonidazole as in untreated mice. The effect was observed only with doses of misonidazole of 1 mg/g or higher given within 2 days prior to i.v. injection of tumor cells. A similar twofold amplification of the effect of LTI occurred when 1 mg/g misonidazole was given 30 min before or 0.5 to 2 hours after irradiation. This increase was independent of the dose of LTI and the absolute number of tumor nodules in the lung. The mechanistic possibilities and clinical relevance of the misonidazole effect are discussed.

Treatment of choice for squamous carcinoma of the tonsillar fossa

The records of 160 patients with squamous cell carcinoma of the tonsillar fossa treated from 1968 through 1979 were reviewed. Biologic behavior, local and regional findings, and other prognostic factors were evaluated. patients were treated by either radiation alone (112 patients), radiation followed by planned neck dissection (31 patients), surgery alone (11 patients), or surgery combined with radiation (6 patients). Analysis of the data supports the recommendation that radiation be used as treatment for T1, T2, and early T3 lesions, whereas surgery alone or combined with radiation is best employed for advanced T3 or T4 tumors. Primary tumor control rates with radiation as the initial modality were 100% for T1 lesions, 89% for T2, 68% for T3, and 24% for T4. In addition, the control of cervical metastases with radiation therapy for patients with neck disease staged N0 through N3b was excellent (95%). In instances where a planned neck dissection was done 5 weeks after radiation, the control of cancer in the neck was 100%. The incidence of distant metastases was 10% and was not affected by the selection of therapy. The 2- and 5-year determinate survival figures for 112 patients treated with radiation therapy alone was 67% and 48% respectively, while 31 patients treated with radiation therapy followed by neck dissection achieved survival rates of 70% (2 year) and 58% (5 year). The criteria for selection of treatment are discussed.

Treatment of squamous carcinoma of the retromolar trigone

Since squamous carcinoma of the retromolar trigone is unusual, there is a paucity of information in the world's literature to use as a reference for selecting treatment and determining pertinent factors affecting prognosis. Consequently, an analysis of the medical records of 110 patients with biopsy proven squamous carcinoma originating in the retromolar trigone, seen and treated entirely at The University of Texas M.D. Anderson Hospital and Tumor Institute at Houston from 1965-1977, with at least 5 years of follow-up, was completed and constitutes the substance of this study. Local-regional control and survival were correlated with age, sex, presenting signs and symptoms, dental status, T and N classification, histologic grading, surgical findings, and the various modalities of treatment. Seventy lesions were staged T1-T2 and 77 patients had N0 necks. Thirty-five patients received a planned combination of surgery and x-ray therapy to the primary and/or neck. A composite resection was performed in 48 patients with the closure accomplished primarily or with a skin graft. The various surgical approaches are critiqued with a favorable emphasis on the marginal resection of the mandible and a modification of the radical neck dissection. The ultimate failure in the primary and the neck was 7% (8/110) and 10% (11/110) respectively. Single modality treatment whether it is surgery or irradiation appears equally adequate regardless of the T or N Stage. However, more T3-T4 cancers were treated initially with surgery. Thirty-six patients developed a second primary cancer of which 29 were in the upper aerodigestive tract. The low 5-year survival of 20% (29/110) reflects a poor salvage of the second primary and a high incidence of intercurrent disease in this elderly group of patients.