Int. J. Cancer: 70, 475–477 (1997) r 1997 Wiley-Liss, Inc. Publication of the International Union Against Cancer Publication de l’Union Internationale Contre le Cancer 13-CIS RETINOIC ACID AND INTERFERON-a 6 IRRADIATION IN THE TREATMENT OF SQUAMOUS-CELL CARCINOMAS Wolfgang HOFFMANN1*, Martina SCHIEBE1, PETER HIRNLE2, Rainer SOUCHON3, Michael CLEMENS4, Iraenus ADAMIETZ5, and Michael BAMBERG1 1Department of Radiotherapy, University of Tübingen, Germany 2Department of Gynecology, University of Tübingen, Germany 3Department of Radiotherapy, General Hospital, Hagen, Germany 4Department of Medical Oncology, University of Tübingen, Germany 5Department of Radiotherapy, University of Frankfrut, Germany Pre-clinical data indicate that retinoid/interferon combinations have significant activity in modulating malignant cell growth, differentiation and programmed cell death in different hematologic and solid tumor systems (Bollag et al., 1992; Hoffmann et al., 1995). Clinically, the combination of 13-cis retinoic acid (13cRA) and interferon-a (IFN-a) has been studied in a variety of tumor types and was identified to have, among others, substantial activity in advanced squamous-cell carcinomas (SCCs) of the skin and the cervix (Lippmann et al., 1992a,b; Alberts et al., 1993; Dmitrovsky and Bosl 1992; Roth et al., 1994). Since radiotherapy (XRT) is a substantial part of the treatment of SCC, the question arises as to whether the therapeutic results obtainable with radiation alone can be further improved by using the additive effect of a systemic treatment with 13cRA and IFN-a. The rationale for this approach is based on experimental data since both IFN and retinoids have been demonstrated to synergistically potentiate the radiation toxicity of human SCC cells (Hoffmann et al., 1994). In addition, it has been shown that vitamin A and its derivates potentiate the response of experimental animal tumors to radiation (Tannock et al., 1972; Seifter et al., 1983). We evaluated prospectively the feasibility and toxicity of such a combination, using 13cRA and IFN together with simultaneous radiation in SCCs of different origin, and compared our results with a group of patients treated systemically with 13cRA and IFN-a alone. PATIENTS AND METHODS Patient selection and study design Adult patients (18–75 years) with histologically confirmed diganosis of SCC were eligible for this study. The eligibility criteria included an adequate performance status (ECOG 0–2); a life expectancy of at least 3 months; and unimpaired bone narrow, liver and renal functions. Patients with brain metastases or severe cardiovascular diseases were excluded. The study was approved by the ethics committee of the Medical Faculty at the Eberhard-KarlsUniversity, Tübingen, Germany. Pre-treatment evaluation included a complete medical history and physical examination, chest X-ray, electrocardiogram, complete blood cell counts and biochemical profile. Conventional radiology, ultrasound and CT scans were performed for tumor measurements. Toxicity and response were determined by WHO criteria. Doses of systemic treatment were reduced if necessary on the basis of the level of toxicity (dose reduction in case of grade III or grade IV toxicity). In patients who received concomitant irradiation, the response was evaluated only if measurable disease outside the irradiation field was present. Comparisons were made between patients receiving 13cRA/IFN-a concomitantly to radiotherapy (group A) and patients receiving systemic treatment alone (group B). Treatment and drug administration Group A. Twenty-seven patients underwent external beam irradiation using linear accelerators. Radiotherapy was administered according to standard irradiation procedures of the distinct tumor entities. Doses given ranged between 50 and 70 Gy in 1.8–2.0 daily fractions over 5–8 weeks (ICRU report 50) depending on tumor type, stage and treatment intention. Patients with cervical cancer received additional brachytherapy using a remote after-loading device equipped with 192Ir, 3 to 6 3 7.0 Gy point A. Patients received 13cRA, 0.5 mg/kg body weight, orally once a day and IFN-a, 3 3 106 UI s.c., 3 times a week. After irradiation was terminated the RA dose was elevated to 1 mg/kg body weight and the IFN dose to 3 3 106 IU s.c. daily. Group B. Thirty patients receiving systemic treatment alone were treated with 1.0 mg/kg body weight 13cRA orally and IFN-a, 3 3 106 UI s.c., once a day. Treatment was maintained for 12 weeks in all patients without progressive disease. For the responding patients, treatment was maintained until disease progression was evident. Mean duration of systemic treatment in both groups was 105 days, with a median of 97.5 days (range 22–239 days). RESULTS Patient population A total of 57 patients were eligible for toxicity and feasibility of the therapeutic regimens performed. Patients’ characteristics are listed in Table I. Hematological toxicity In both treatment groups A and B, myelotoxicity was moderate and did not exceed WHO grade II in most cases. In 3 patients out of group B, who were irradiated for cervical (n 5 2) and head and neck (n 5 1) cancer, WHO grade III leucopenia (1.0–1.9/µl) led to interruption of trial medication for 7 days. In group A, only 2 patients developed grade III toxicity, with leucopenia in a head and neck cancer patient and in one patient with esophageal cancer with anemia combined with thrombocytopenia, causing treatment interruption for 7 and 10 days, respectively. None of the patients required blood transfusion or antibiotic treatment. Table II summarizes the hematological side effects. Non-hematological toxicity Tables III and IV demonstrate the toxicity data and mean severity of side effects for both treatment groups. Fatigue and ‘‘flu-like symptoms’’ occurred in 35% of all cases. Fever on the days of IFN medication could easily be managed using paracetamol 3 3 500 mg p.o. and was always transient. Three out of 5 patients with head and neck cancer in group A developed grade III mucositis in the course of radiotherapy. One head and neck cancer patient developed grade III cheilitis with dry skin desquamation. Parenteral alimentation did not become necessary in any case. No severe mucositis or skin toxicity was observed in the patient group without concomitant irradiation. Combined treatment (RA/ IFN 1 RT) induced slightly pronounced toxicity scores of mucositis and skin toxicity compared with patients treated systemically only. Diarrhea was rare (9 patients). Only 2 women with cervical cancer in group A and 1 cervical cancer patient in group B developed more pronounced diarrhea. In all other patients, gastro- *Correspondence to: Department of Radiotherapy, University of Tübingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany. Fax: 7071 29 58 94. HOFFMANN ET AL. 476 TABLE I – PATIENTS’ CHARACTERISTICS Group A (13cRA/IFN-a/XRT) Group B (13cRA/IFN-a) 27 12 15 0–1 27–71 30 18 12 0–2 38–70 13 5 8 1 12 10 5 3 Elegible (total n 5 57) Male Female Performance status (ECOG) Age (range, years) Tumor type Cervix Head and neck NSLC Esophagus DISCUSSION TABLE II – HEMATOLOGICAL TOXICITY WHO grade 1-2-3-4 Tumor type Leucopenia Thromboeytopenia Group A (13cRA/IFN-a/XRT) Cervix Head and neck NSCLC Esophagus Group B (13cRA/IFN-a) Cervix Head and neck NSCLC Esophagus Anemia 2-2-2-0 0-2-1-0 2-1-0-0 0-0-0-0 2-0-0-0 0-0-0-0 0-0-0-0 0-0-0-0 2-2-0-0 3-0-0-0 1-1-0-0 0-1-0-0 3-3-0-0 1-3-1-0 0-0-0-0 1-0-0-0 0-0-0-0 0-0-0-0 0-0-0-0 0-0-1-0 3-4-0-0 1-2-0-0 0-1-0-0 1-0-1-0 TABLE III – NON-HEMATOLOGICAL TOXICITY WHO grade 1-2-3-4 Tumor type Lung The overall response rate of all 16 cervical cancer patients evaluable for response was 5 out of 16 (31%; 95% CI 11–59%). Mean duration of response was 106 days in patients with cervical cancer (median 92.5 days, range 0–239 days). Mean time to progression was 135 days for patients with cervical cancer, with a median of 217 days (range 22–239 days) (Table 5). Nausea Group A (13cRA/IFN-a/XRT) Cervix 3-1-0-0 4-2-3-0 Head and neck 4-0-1-0 2-0-0-0 NSCLC 4-1-0-1 4-2-0-0 Esophagus 0-0-0-0 0-0-0-0 Group B (13cRA/IFN-a) Cervix 1-0-0-0 1-2-1-0 Head and neck 3-1-1-0 2-1-1-0 NSCLC 6-2-1-0 4-0-0-0 Esophagus 0-0-0-0 2-1-0-0 Mucositis Dry skin Diarrhea desquamation 5-3-0-0 0-0-3-0 3-1-0-0 1-0-0-0 2-8-0-0 1-2-1-0 0-5-0-0 0-0-0-0 3-1-1-0 1-0-0-0 1-0-0-0 0-0-0-0 2-1-0-0 8-0-0-0 1-0-0-0 1-0-0-0 0-3-1-0 2-5-0-0 2-2-0-0 0-3-0-0 0-0-1-0 0-0-0-0 0-0-0-0 0-1-0-0 intestinal side effects, such as nausea, were mild and transient, occurring equally in both treatment groups. Pulmonary symptoms were pre-existing due to obstructive lung disease and were not exaggerated by systemic treatment. More pronounced pulmonary side effects were documented in one patient with non-small-cell lung cancer (NSCLC) suffering from grade IV pulmonary toxicity. This patient was a 53-year-old woman presenting with an advanced NSCLC. Systemic treatment with RA/IFN and radiotherapy of the primary tumor led initially to a good partial response inside and outside the irradiation field. However, 2 months after completion of radiotherapy the patient developed severe pneumonitis and finally died with progressive respiratory failure, which was induced by pulmonary fibrosis and massive tumor progression. Pathologic examination revealed a change of histo-morphological appearance with a small cell component which initially was not apparent. Response Group A. Four partial responses were observed outside the irradiation field (2 3 cervical cancer, 1 3 head and neck cancer, 1 3 NSCLC). Median duration of response was 152 days and 50 days for the patients with cervical cancer. Group B. Treatment with RA/IFN-a alone led to 3 partial responses in patients with cervical cancer. All together, 7 patients out of a total of 36 evaluable for response responded to the systemic treatment with a partial remission (19.4%; 95% CI 8–35%). In patients with solid tumors, toxicity of systemic treatment with RA/IFN alone has been previously described to be mild and to consist mainly of fatigue and skin changes (Lippmann et al., 1992b; Tomna et al., 1994). We have integrated the regimen of 13cRa and IFN-a into standard comprehensive radiotherapy of SCCs of different sites. In combination with radiotherapy, acute toxicity is revealed to be moderate and generally does not exceed the toxicity seen with radiation only. In the present study, dose escalations for defining dose-limiting toxicity and maximum tolerated dose have not been performed in order to not compromise curatively intended treatment by unexpected toxicity. With the regimen used, the comparison between toxicity of combination treatment with a group of patients treated with systemic treatment alone revealed a very mild increase of acute toxicity only. Hematological toxicity was mild and transient in both treatment groups, necessitating treatment interruption in a few cases only. Among non-hematological manifestations of toxicity in patients with cervical cancer, diarrhea was more pronounced with systemic treatment plus radiation. One other preliminary report of such a combination describes the toxicity in an ongoing phase II trial in patients with cervical cancer using 13cRA (0.5–1.0 mg/kg/body weight) and IFN 6 3 106 IU/daily in combination with CO60 radiation (Lippmann et al., 1993). The results reported so far describe severe radiation-induced proctitis as being dose-limiting. We used modern linear accelerators and a 4-field box technique and administered uniform doses of 0.5 mg/kg 13cRA and 3 3 106 IU IFN-a in our study. With this regimen, proctitis has not been observed. In patients with head and neck cancer, mucositis was more severe when the treatment was combined with radiotherapy. Cheilitis as a known side effect of RA treatment was not found to be exaggerated with radiation since the lips have not been included in the target volume. The only case with WHO-IV toxicity was seen in a female patient with NSCLC (group A) who initially responded well to treatment with 13cRa/IFN and XRT. Both the primary tumor and the lung metastases outside the irradiation field showed a partial response after completion of radiotherapy. The patient developed severe pneumonitis 8 weeks later and finally died as a consequence of massive tumor progression and respiratory failure from interstitial fibrosis. The change in histology from NSCLC to SCLC upon autopsy confirms the activity of the systemic treatment which eradicated the squamousa cell compound. Furthermore, microscopic examination of the lung revealed diffuse pneumonitis as occasionally induced by radiotherapy, which in this case might have been potentiated by IFN-a (Dritschiko et al., 1982; Davis et al., 1992). Systemic treatment in combination with irradiation led to remissions in group A, with 4 partial responses outside the irradiation field (2 3 cervical cancer, 1 3 NSCLC and 1 3 head and neck cancer). Together with the 2 partial responses in cervical cancer observed in group B, out of all 16 patients with cervical cancer evaluable for responses, the partial response rate was about 30%. This confirms other observations describing only casuistic responses in patients with head and neck tumors, NSCLC or esophageal cancer, suggesting that biological differences among different tumors, including different etiologies, account for the responsiveness of skin and cervical cancers and the relative failure of other SCCs (Roth et al., 1994; Toma et al., 1994) Another possible explanation is under investigation—namely, whether the coincidence of cervical cancers with HPV (human papilloma viruses)-infection could explain the susceptibility of these tumors to this kind of treatment since both IFN-a and retinoids are known to exert anti-viral effects (Lippman et al., 1993; Hoffmann et al., 1995). Since the combination of RA and IFN-a has been shown to 13cRA, INF-a 6 RADIOTHERAPY IN SCC 477 TABLE IV – MEAN SEVERITY OF SIDE EFFECTS Tumor type Cervix Side effects Anemia Leucopenia Thrombocytopenia SGOT/SGPT Mucositis Nausea Diarrhea Pulmonary toxicity Fever Skin/cheilitis Head and neck Lung Group A Group B Group A Group B Group A Group B 0.46 0.92 0.15 0.15 0.85 1.311 0.62 0.38 0.38 1.381 0.92 0.75 0.00 0.50 0.33 0.66 0.25 0.08 0.70 0.75 0.60 1.401 0.00 0.00 1.801 0.40 0.20 1.401 1.201 1.601 0.50 1.001 0.00 0.20 0.80 0.70 0.00 1.201 0.40 1.201 0.38 0.50 0.00 0.00 0.63 1.001 0.13 1.251 1.001 1.251 0.40 0.00 0.00 0.20 0.20 0.80 0.00 1.401 0.40 1.201 Mean severity (MS) of side effects (WHO toxicity score). Values represent calculated mean of side effects. MS 5 n 1 ? 1 1 n 2 ? 2 1 n3 ? 3 1 n 4 ? 4 n0 1 n1 1 n2 1 n3 1 n4 n1, number of cases with Grade 1 toxicity; n2, number of cases with Grade 2 toxicity; n3, number of cases with Grade 3 toxicity; n4, number of cases with Grade 4 toxicity.–1WHO values $1. be effective in advanced SCC and since the addition of ionizing radiation tests on both a pre-clinical and clinical rationale, we conclude that this treatment is indeed feasible. We suggest that further evaluation of the 13cRA/IFN combination in phase I/II trials as an adjunct to radiotherapy might define the ultimate role of the combination. However, patients should be carefully monitored for the onset of pulmonary toxicity as well as for other side effects, such as mucositis, skin reactions or diarrhea. ACKNOWLEDGEMENTS The assistance of Dr. I. Zuna, Heidelberg with the documentation of clinical data is gratefully acknowledged. 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