Split-course versus continuous pelvis irradiation in carcinoma of the uterine cervix: a prospective randomized clinical trial of the Radiation Therapy Oncology Group

Radiation therapy oncology group gynecologic oncology working group: comprehensive results

The purpose of this report was to comprehensively describe the activities of the Gynecologic Oncology Working Group within the Radiation Therapy Oncology Group (RTOG). Clinical trials will be reviewed as well as translational science and ancillary activities. During the past 40 years, a myriad of clinical trials have been performed within the RTOG with the aim of improving overall survival (OS) and decreasing morbidity in women with cervical or endometrial cancer. Major study questions have included hyperbaric oxygen, neutron radiotherapy, altered fractionation, hypoxic cell sensitization, chemosensitization, and volume-directed radiotherapy.RTOG 7920 demonstrated improvement in OS in patients with stages IB through IIB cervical carcinoma receiving prophylactic para-aortic irradiation compared to pelvic radiation alone. RTOG 9001 demonstrated that cisplatin and 5-FU chemoradiotherapy to the pelvis for advanced cervix cancer markedly improved OS compared to extended field radiotherapy alone. More recent trials have used radioprotectors, molecular-targeted therapy, and intensity-modulated radiation therapy. Ancillary studies have developed clinical target volume atlases for research protocols and routine clinical use. Worldwide practice patterns have been investigated in cervix, endometrial, and vulvar cancer through the Gynecologic Cancer Intergroup. Translational studies have focused on immunohistochemical markers, changes in gene expression, and miRNA patterns impacting prognosis.The RTOG gynecologic working group has performed clinical trials that have defined the standard of care, improved survival, and added to our understanding of the biology of cervical and endometrial cancers.

Hypoxia and anaemia in patients with cancer of the uterine cervix

Hypoxia and/or anaemia have an adverse prognostic impact in locally-advanced cancers of uterine cervix. Moreover, these parameters are independent of other well-known prognostic factors. However, the mechanisms by which treatment efficacy and survival are compromised by anaemia are not fully understood. Although it is clear that erythropoietin can reduce the need for transfusions for cancer patients with anaemia, there is no proof that the use of erythropoietin is in any way superior to transfusions with respect to the impact on clinical outcome, especially for patients receiving radiation therapy. Whether haemoglobin levels at the start of therapy, during therapy, or at the end of therapy are of prognostic value for better disease-free and overall survival, are matters for further studies as is the question of the best option for increasing the level of the patient's haemoglobin.

Comparison of low and high dose rate brachytherapy in the treatment of uterine cervix cancer. Retrospective analysis of two sequential series

PURPOSE

This retrospective analysis aims to report on the comparative outcome of cervical cancer patients treated with low dose rate (LDR) and high dose rate (HDR) brachytherapy.

METHODS AND MATERIALS

From 1989 to 1995, 190 patients were treated with low dose rate (LDR) brachytherapy (LDR group) and from 1994 to 2001, 118 patients were treated with high dose rate (HDR) brachytherapy (HDR group). FIGO stage distribution for the LDR group was Stage I: 6.3%; Stage II: 57.4%; and Stage III: 36.3% and for the HDR group Stage I: 9.3%; Stage II: 43.2%; and Stage III: 47.4%. All patients were treated with telecobalt external-beam radiotherapy (EBR). Median doses of LDR brachytherapy at Point A were 40 Gy and 50 Gy for patients treated with 1 and 2 implants, respectively. All patients from the HDR group were treated with 24 Gy in 4 fractions of 6 Gy to Point A. Survival, disease-free survival, local control, and late complications at 5 years, were endpoints compared for both groups.

RESULTS

Median follow-up time for LDR and HDR groups was 70 months (range, 8-127 months) and 33 months (range, 4-117 months), respectively. For all stages combined, overall survival, disease-free survival, and local control at 5 years were better in the LDR group (69% vs. 55%, p = 0.007; 73% vs. 56%, p = 0.002; and 74% vs. 65%; p = 0.04, respectively). For clinical Stages I and II, no differences was seen in overall survival, disease-free survival, and local control at 5 years between the two groups. For clinical Stage III, overall survival and disease-free survival at 5 years were better in the LDR group than in the HDR group (46% vs. 36%, p = 0.04 and 49% vs. 37%, p = 0.03, respectively), and local control was marginally higher in the LDR group than in the HDR group (58% vs. 50%, p = 0.19). The 5-year probability of rectal complications was higher in the LDR group than in the HDR group (16% vs. 8%, p = 0.03) and 5-year probability of small bowel and urinary complications was not statistically different between the the LDR group and the HDR group (4.6% vs. 8.9%, p = 0.17 and 6% vs. 3%, p = 0.13, respectively).

CONCLUSIONS

This comparative series suggests similar outcome for Stages I and II patients treated with either HDR or LDR brachytherapy. Lower overall and disease-free survival and marginally lower local control were observed for Stage III patients treated with HDR brachytherapy. Less late rectal complications were observed in the HDR group patients. These findings were probably the result of the relatively low HDR brachytherapy dose delivered at Point A.

Radiation Therapy Oncology Group clinical trials for carcinoma of the cervix

Grigsby PW. Radiation Therapy Oncology Group clinical trials for carcinoma of the cervix. The purpose of this paper is to review the primary data of the clinical trials performed by the Radiation Therapy Oncology Group (RTOG) for patients with carcinoma of the uterine cervix. The trials, their strengths, limitations, and the implications of the results are discussed. During the past 25 years there have been several clinical trials performed by the RTOG to test various hypotheses for improving local control and survival for patients with carcinoma of the uterine cervix. The major research themes that have been appraised are the use of hyperbaric oxygen, altered fractionation radiotherapy, hypoxic cell sensitization, chemo-sensitization, prophylactic paraaortic irradiation, and neutron radiotherapy. There are two general research themes. The initial RTOG trials for cervical cancer attempted to address the issues of tumor volume and hypoxic cells while the latter studies addressed these issues and the issue of micrometastatic disease. The phase III clinical trials performed by the RTOG have not demonstrated a local control or survival advantage in the experimental arm with the use of hyperbaric oxygen, split-course radiotherapy, hypoxic cell sensitization, or neutron radiotherapy. Acceptable toxicity and efficacy results were shown in phase II studies evaluating twice-daily irradiation and chemo-sensitization. The positive phase III trials were RTOG 79-20 which evaluated prophylactic paraaortic irradiation in patients with bulky stages IB, IIA, and IIB disease, and RTOG 90-01 which evaluated concurrent chemotherapy. Results of more recent clinical trials are pending their completion.

Treatment of carcinoma of the uterine cervix with concomitant cisplatin, 5-fluorouracil and split course hyperfractionated radiotherapy

To improve local and systemic control of bulky (>4 cm) and/or advanced primary cancer of the uterine cervix, 35 patients were treated with concomitant cisplatin (CDDP), 5-fluorouracil (5-FU) and split course hyperfractionated radiotherapy. Radiation was administered to the pelvis in five-day courses at a dose of 1.5 Gy twice daily every 21 days until a median dose of 45 Gy was reached. 15 Gy more were administered to involved parametrium or central tumor by external radiotherapy or brachytherapy. The irradiated zone was extended to include paraaortic lymph nodes if necessary. CDDP was administered at a dose of 20 mg m(-2) and 5 FU at a dose of 500 mg m(-2) from day one to day five of each course. The median number of combined treatment courses per patient was four (1-6). Local responses were obtained in 19 out of 24 patients in whom evaluation was feasible (i.e. who did not undergo surgery prior to combined therapy). Median survival was not attained with a median follow up of 33 months, three year overall survival was 62% and 52% in patients with local control and in the whole population respectively. Several patients with stage III and IV tumors achieved a very long survival. Acute toxicity was manageable but three patients required surgical repair of late radiation complications. This combined chemotherapy and radiotherapy resulted in good local control and did not rule out surgery.

Evolution of the Radiation Therapy Oncology Group clinical trials for head and neck cancer

During the past 25 years, the Radiation Therapy Oncology Group (RTOG) has played a major role in head and neck cancer clinical research. The major research themes for recent and currently active trials have been: (a) combined modality therapy, (b) altered fractionation radiotherapy, (c) hypoxic cell sensitizers, (d) organ preservation, (e) chemoprevention, and (f) clinical/laboratory correlations. For advanced operable disease, the RTOG showed improved local-regional control with postoperative radiotherapy as compared to preoperative radiotherapy for carcinoma of the supraglottic larynx and hypopharynx. This established the use of surgery followed by postoperative radiotherapy as the standard treatment in subsequent RTOG and Intergroup trials for operable disease. For advanced inoperable disease, the RTOG demonstrated the feasibility of testing altered fractionation radiotherapy in a multiinstitutional clinical trials setting. A Phase III trial comparing hyperfractionation and accelerated fractionation to conventional fractionation is now in progress. Phase I/II combined modality studies established the efficacy of concurrent high-dose cisplatin and radiotherapy in the treatment of advanced disease and provided the basis for further testing in Phase III trials for nasopharyngeal carcinoma, larynx preservation, and high-risk advanced operable disease. Analysis of the extensive RTOG Head and Neck Cancer database established the incidence of second malignancies and their adverse impact on patients whose initial tumors were cured by radiotherapy, and provided the basis for chemoprevention trials. Recursive partitioning analysis identified 6 distinct prognostically homogeneous patient groups based on pretreatment tumor or patient characteristics and/or treatment variables. Retrospective analysis identified tumor p105 antigen density as an independent prognostic indicator in patients irradiated for head and neck cancer. Future trials will continue to focus on the reduction of morbidity and mortality, and improvement of the quality of life of head and neck cancer patients through innovative radiotherapy delivery, multimodality approaches, use of chemical and biological modifiers, and other novel therapies, identification of clinical and biological prognostic indicators, and prevention or diminution of acute morbidity and late complications of the disease and its treatment.

Carcinoma of the uterine cervix. I. Impact of prolongation of overall treatment time and timing of brachytherapy on outcome of radiation therapy

PURPOSE

Some studies have described decreased pelvic tumor control and survival rates in invasive carcinoma of uterine cervix when the overall time in a course of definitive irradiation is prolonged. We attempt to confirm or deny these observations and evaluate the impact of timing of brachytherapy on outcome. We also explore the hypothesis that more extensive tumors technically require prolongation of the course of irradiation; thus, decreased tumor control and survival in these patients may not necessarily be the result of time/dose factor.

METHODS AND MATERIALS

Records of 1,224 patients (Stage IB to III) treated with definitive irradiation (combination of external beam and two intracavitary insertions to deliver doses of 70 to 90 Gy to point A) were reviewed. Follow-up was obtained in 97% of the patients (median, 12 years; minimum, 3 years; maximum, 28 years). The relationship between outcome and overall treatment time and time of intracavitary insertions was analyzed in each stage and according to tumor size/extent.

RESULTS

There was strong correlation between overall treatment time (OTT) and tumor stage (< or = 7 weeks: 81% for Stage IB; 74% for Stage IIA; 52% for Stage IIB; and 47% for Stage III). Interruptions of therapy accounting for prolongation of treatment time occurred in 25-30% of patients, most frequently because of holidays and weekends and side effects of therapy. Overall treatment time had a major impact on pelvic tumor control in Stages IB, IIA, and IIB; in Stage IB 10-year actuarial pelvic failure rates were 7% with OTT < or = 7 weeks, 22% with 7.1 to 9 weeks, and 36% with > 9 weeks (p < or = 0.01). For Stage IIA the corresponding values were 14%, 27%, and 36% (p = 0.08), and in Stage IIB pelvic failure rates were 20%, 28%, and 34%, respectively (p = 0.09). In Stage III, pelvic failure was 30%, 40%, and 50%, respectively (p = 0.08). There was also a strong correlation between OTT and 10-year cause-specific survival (CSS); in Stage IB rates were 86% with OTT of < or = 7 weeks, 78% for 7.1 to 9 weeks, and 55% for > or = 9 weeks (p < 0.01). The corresponding rates in Stage IIA were 73%, 41%, and 48% (p < or = 0.01). For patients with Stage IIB, CSS rates were 72% for OTT < or = 7 weeks, 60% for 7.1 to 9 weeks, and 70% for > 9 weeks (p = 0.01). Patients with Stage III disease had 45% 10-year CSS when treatment was delivered in 9 weeks or less and 36% for longer overall times (p = 0.16). In multivariate analysis of patients with Stage IB and IIA, OTT and clinical stage were the most important prognostic factors for pelvic tumor control, disease-free survival, and CSS. Tumor size was a prognostic factor for CSS. In Stages IIB and III, OTT, clinical stage, unilateral or bilateral parametrial invasion, and dose to point A were significant prognostic factors for pelvic tumor control, disease-free survival, and CSS. Prolongation of time had a significant impact on pelvic tumor control and CSS regardless of tumor size, except in Stage IB tumors < or = 3 cm. Regression analysis confirms previous reports that prolongation of OTT results in decreased pelvic tumor control rate of 0.85% per day for all patients, 0.37% per day in Stages IB and IIA, 0.68% per day in Stage IIB, and 0.54% for Stage III patients treated with > or = 85 Gy to point A. Performance of all intracavitary insertions within 4.5 weeks from initiation of irradiation yielded decreased pelvic failure rates in some groups of patients (8.8 vs. 18% in Stage IB and IIA tumors < or = 4 cm and 12.3 vs. 35% in Stage IIB) (p < or = 0.01).

CONCLUSIONS

Prolongation of treatment time in patients with Stage IB, IIA, IIB, and III carcinoma of the uterine cervix has a significant impact on pelvic tumor control and CSS. The effect of OTT was present regardless of tumor size except in Stage IB tumors < or = 3 cm.

Planned and unplanned gaps in radiotherapy: the importance of gap position and gap duration

Local tumour control in 971 patients with squamous carcinoma of the supraglottic larynx has been examined in relation to the occurrence of gaps in radiation therapy. The minimum follow-up time was 3 years. The reasons for a gap in radiotherapy fell into four categories: independent of the patient (national holidays, machine break-down, etc.), planned gaps (split-course therapy), severe normal-tissue reactions, and intercurrent disease. Only 11.7% of patients had no gap at all, 75.5% a single gap, and 2.1% had more than four gaps. The probability of tumour control increased with dose in all patient sub-groups; the average percentage increase for a 1% increase in dose was 4.3. The data were subjected to multivariate analysis, leading to the following conclusions. Patients in whom there was a single gap showed a remarkable trend of local control: if the gap began before day 19 after the start of therapy, the local tumour control was considerably below that in patients who did not suffer a gap in treatment. The local tumour control in patients whose gap began at day 20-29 was indistinguishable from that in patients who had no gap in treatment. A gap further towards the end of treatment was again associated with a severe drop in local control. This trend was independent of the recorded cause of the gap. The mechanism of this phenomenon is not clear. The effect of the timing of a treatment gap appears in this data set to have had a considerable impact on outcome and our observations should stimulate further study of this phenomenon in other clinical settings.

Increased chronic bowel complications with split-course pelvic irradiation

PURPOSE

To assess the possible impact of various treatment factors including split-course versus continuous course treatment on the incidence of chronic bowel complications in patients receiving adjuvant pelvic radiotherapy.

METHODS AND MATERIALS

A retrospective review was performed of records of 153 patients treated with adjuvant external beam pelvic radiation therapy without brachytherapy for endometrial and colorectal carcinomas. Continuous course radiotherapy was administered in 91 patients (59%) and 62 patients (41%) received split course treatment with a planned 2 week mid-treatment break. Mean pelvic dose and daily fraction size were 51.4 and 1.71 Gray, respectively. Multiple patient and treatment variables were assessed for their possible relationship to chronic bowel complications. Univariate and multivariate statistical analyses were carried out.

RESULTS

Twenty-seven patients (18%) developed chronic bowel complications at a median interval of 12 months after radiotherapy. Of all factors analyzed, only the use of split course technique was associated with a significantly higher rate of chronic bowel injury and decreased complication-free survival (p = 0.009).

CONCLUSION

This study supports earlier suggestions that the use of split course rather than continuous course pelvic radiotherapy can increase late intestinal complication rates. Possible pathophysiologic mechanisms are discussed.

The effect of volume of disease in patients with carcinoma of the uterine cervix

This is a retrospective study of 635 consecutively treated patients with FIGO Stage IIB or IIIB carcinoma of the uterine cervix. All patients were treated definitively with radiation therapy. The effect of volume of disease on outcome was studied. The 5-, 10-, and 15-year disease-free survivals (DFS) for the 346 Stage IIB patients were 64%, 61%, and 58%, respectively. Corresponding DFS for the 289 Stage IIIB patients were 40%, 38%, and 34%, respectively. The presence of bilateral parametrial invasion did not alter the 10-year DFS in Stage IIB patients (61% vs 64%, p = 0.60) but did decrease it in Stage IIIB patients (34% vs 50%, p = 0.006). Patients with both Stage IIB and IIIB cancers and central bulky disease (greater than or equal to 5 cm in diameter) had decreased DFS when compared to those without central bulky disease. Stage IIB patients with the lateral half of the parametrium involved had a decreased 10-year DFS in comparison with medial half involvement (52% vs 68%, p = 0.004). The total pelvic failure rate was 23% for Stage IIB and 41% for Stage IIIB patients. Central bulkiness increased the pelvic failure rate by about 11% for all patients. Bilateral parametrial disease increased the pelvic failure rate in Stage IIIB patients but not in patients with Stage IIB disease. The total pelvic failure rate for Stage IIB patients was greater in those whose disease extended into the lateral parametrium. Multivariate analysis was done using stage, lateral pelvic wall dose, parametrial disease, central bulkiness, age, and total dose to point A as variables. With local control as the endpoint, only stage (IIB vs IIIB) was significant (p = 0.008). Using DFS as the endpoint, stage (p = 0.0001) and central bulkiness of tumor (p = 0.026) were significant. Complications were not increased in patients with bulky or bilateral disease. We conclude that there is justification for subdividing FIGO Stage IIIB patients into those with unilateral or bilateral disease; however, these data do not support such a division for FIGO Stage IIB patients. These latter patients would be better analyzed with reference to medial versus lateral parametrial extension because of the difference in pelvic control and survival.

Radiotherapy with or without misonidazole for patients with stage IIIB or stage IVA squamous cell carcinoma of the uterine cervix: preliminary report of a Radiation Therapy Oncology Group randomized trial

Between August 1980 and November 1984, 119 patients with FIGO Stage IIIB or IVA squamous cell carcinoma of the uterine cervix were randomized to receive radiation therapy (4600 cGy pelvis plus 1000 cGy parametrial boost) followed by intracavitary or external boost to the primary with or without misonidazole (MISO) (400 mg/m2 daily 2 to 4 hours prior to radiation therapy). Patients in the two treatment groups were evenly distributed with respect to stratification variables including stage, Karnofsky Performance score, and positivity of para-aortic nodes. Eighty-nine percent of patients had Stage IIIB disease and 88% had a Karnofsky score of 80 or better. Seventy-five percent of patients treated with radiation therapy alone and 79% of patients treated with radiation therapy plus MISO received a boost via intracavitary application. Life threatening (Grade 4) complications occurred in 5 patients receiving radiation therapy alone and one patient receiving radiation therapy plus MISO. MISO toxicity (Grade 3) was limited to severe nausea and vomiting in two patients. With 119 evaluable patients and a median follow-up of 33 months, 64% of patients receiving radiation therapy alone are alive at 18 months compared with 54% for patients assigned to radiation therapy plus MISO. The median survival for patients treated with radiation therapy alone and radiation therapy plus MISO was 1.9 years and 1.6 respectively. At this point in the study the difference in survival is inconsistent with the hypothesis of an improvement associated with MISO. There have been 23 deaths among the 49 patients treated with radiation therapy plus MISO who have been followed for at least 18 months compared with 17 deaths in 48 patients treated with radiation therapy alone. The chance of observing this number of deaths with radiation therapy plus MISO if the addition of MISO improves survival by 10 to 20% is 0.003 and less than 0.001, respectively. The addition of MISO to radiation failed to improve survival for these patients. The results cannot be explained by an uncharacteristically high survival on the radiation therapy alone arm or by an imbalance in the distribution of prognostic factors. Local-regional control remains a problem in the management of patients with advanced cervical carcinoma. More effective and less toxic radiosensitizing agents are needed.