RTOG 0131: Phase II trial of pre-irradiation and concurrent temozolomide in patients with newly diagnosed anaplastic oligodendrogliomas and mixed anaplastic oligodendrogliomas: Relationship between 1p/19q status and progression-free survival

1517

Background: In a previous report, we showed in patients with newly diagnosed anaplastic oligodendrogliomas (AOs) and mixed anaplastic oligoastrocytomas (MAOs) that temozolomide (TMZ) can be given concurrently with radiation therapy (RT) with acceptable toxicity. We have now evaluated the efficacy of this regimen and correlated durability of response with tumor 1p/19q genotype. Methods: A phase II study was performed to evaluate the use of pre-RT TMZ followed by concurrent RT and TMZ in patients with newly diagnosed AO or MAO. The primary endpoint was to determine the pre-RT TMZ six-month progression rate, and secondary endpoints included progression-free survival and overall survival. Results: 40 eligible patients were entered into the trial. Thirty-two patients completed 6 months of pre-RT TMZ and concurrent RT and TMZ. Of the remaining eight patients, 4 withdrew due to toxicity and 4 other patients withdrew from study without evidence of toxicity or pre-RT progression. 1p/19q data are available in 37 cases; 23 tumors had loss of heterozygosity (LOH) of both 1p and 19q (double-deleted) while 14 tumors had LOH of either 1p or 19q (n = 3), or no LOH (n = 11). To date, 11 patients have experienced tumor progression; 1p/19q data are available for 10 of these cases (2 are double-deleted (2/23 = 9%), 8 have at least one intact chromosome (8/14 = 57%). Kaplan-Meier analysis demonstrates that progression free survival is significantly better for the double-deleted group (median time to progression not reached) than for the intact group (median time to progression = 15.2 months, p = 0.001). Overall survival is 98% (39/40) with a median follow-up of 17.5 months (2.8 - 31.1 months). Conclusions: LOH of both 1p and 19q is strongly correlated with a durable response of AO and MAO to a combined regimen of chemotherapy and radiation therapy. Tumors that are intact at 1p and/or 19q progress early despite an aggressive therapeutic regimen. These results suggest that future clinical trials should be prospectively stratified by tumor 1p/19q genotype.

[Table: see text]

An update of phase II results from RTOG 0211: A phase I/II study of gefitinib with radiotherapy in newly diagnosed glioblastoma

1527

Background: The epidermal growth factor receptor (EGFR) pathway is commonly deregulated in GBMs and its activity has been associated with treatment resistance in preclinical models. Accordingly, the Radiation Therapy Oncology Group (RTOG) recently conducted a Phase I/II study of Gefitinib, an EGFR tyrosine kinase inhibitor, in combination with radiotherapy for newly-diagnosed glioblastoma (GBM) patients. Methods: 178 GBM patients were entered on RTOG 0211 (Phase I: 31 patients and Phase II: 147 patients). The maximum tolerated dose (MTD) of Gefitinib was determined to be 500mg in non-EIACD patients, and the Phase II component of RTOG 0211 was continued at this dose level during radiation and as maintenance for 18 months afterward or until disease progression. Results: 119/147 patients completed treatment per protocol and/or with acceptable deviation. The median survival time for all patients in the study was 11.0 months. Progression-free survival was 5.1 months for all patients. When considering only patients who were treated per protocol, the median survival of RTOG 0211 patients was 11.5 months, compared to 11.0 months for historical controls treated in previous RTOG studies (p=0.14). RPA Class IV patients appeared to derive the greatest benefit from Gefitinib when combined with radiotherapy compared to historical controls, although not reaching statistical significance. Molecular and genetic profiling efforts are underway to determine which GBM patients derive greatest benefit from Gefitinib in the upfront setting, which will be reported at the time of the annual meeting. These include markers such as EGFRvIII and PTEN, which have been recently reported to be associated with response to anti-EGFR agents in the recurrent setting, and members of key signal transduction pathways regulated by EGFR. Conclusions: The observed survival advantage of newly-diagnosed GBM patients treated with Gefitinib in combination with radiotherapy compared to historical controls treated on previous RTOG studies does not reach statistical significance. Molecular and genetic profiling efforts are underway to identify subsets of GBM patients who might derive the greatest benefit from Gefitinib in the upfront setting.

No significant financial relationships to disclose.

Prospective neurocognitive effects and quality of life (QOL) in patients with multiple brain metastases receiving whole brain radiation (WBRT) ± thalidomide on radiation therapy oncology group (RTOG) trial 0118

8589

Background: RTOG 0118 was a randomized trial of WBRT (37.5 Gy/15 fractions) ± thalidomide in patients (pts) with brain metastases, which showed no effect on survival (Knisely et al, ASCO, 2005). This analysis examined the relationship between neurocognitive progression (NCP) and QOL in patients on both arms. Methods: NCP was assessed with the Folstein Mini-Mental Status Exam (MMSE) and QOL with the Spitzer QOL Index (SQLI). Pts with MMSE scores below age/education adjusted cutoff levels were considered to have NCP. T-test and Chi-Square statistics were used to determine significant differences in NCP and QOL between the two treatment arms over time. Results: Of 176 pts, 88 and 92% had SQLI and MMSE scores at baseline (43% were below the MMSE cutoff). Baseline SQLI (but not MMSE) was a significant predictor for OS (p=0.034). From baseline, SQLI and MMSE compliance rates were 74 and 60% at 1–2 months (mo), 37 and 29% at 4 mo, and 21 and 19% at 6 months, respectively. While QOL was stable, those who failed to meet MMSE cutoffs increased by 60% by 6 mo, on both study arms. Although a weak correlation (r=.23) existed at baseline between QOL and MMSE for both the WBRT (0.04) and WBRT/thalidomide (0.058) arms, there was no correlation beyond baseline. Conclusions: Baseline QOL is a significant predictor of OS. While QOL remained essentially stable, the degree of neurocognitive decline (60%) over time is concerning. These findings suggest the importance of these outcome measures in pts with brain metastases and the need for interventions to conserve cognitive status. RTOG is developing a trial to study the role of preventive strategies for NCP in brain metastases.

No significant financial relationships to disclose.

Initial report of Radiation Therapy Oncology Group (RTOG) 9802: Prospective studies in adult low-grade glioma (LGG)

1500

Background: Treatment of adult LGG is controversial. Favorable patients (pts) (age <40 years [yrs] who undergo gross total resection [GTR]) are typically observed. Unfavorable pts (age ≥40 who have subtotal resection [STR] or biopsy [B]) are usually given initial radiation therapy (RT), reserving chemotherapy (historically procarbazine, CCNU and vincristine [PCV]) for recurrence. In 1998, the RTOG, in conjunction with SWOG, NCCTG, and ECOG initiated prospective studies of adult LGG, the results of which are reported herein. Methods: Favorable pts were observed postoperatively in a single arm Phase II study (Arm 1). Unfavorable pts were stratified by age, histology, KPS, and presence/absence of contrast enhancement on preoperative magnetic resonance imaging and randomized to either RT alone (54Gy in 30 fractions to a local treatment field) (Arm 2) or RT followed by 6 cycles of standard dose PCV (Arm 3). Reported results include overall survival (OS) rate, median overall survival time (MOST), progression-free survival (PFS) rate, and median progression-free survival time (MPFST). Survival data are compared using Wilcoxon p-values. Results: A total of 362 eligible/analyzable pts were accrued between 1998 and 2002. Median follow-up time is 4 years. For the 111 favorable pts observed on Arm 1, OS at 2- and 5-yrs is 99% and 94%. PFS at 2- and 5-yrs is 82% and 50%. For the 251 unfavorable pts on Arms 2 (RT alone) and 3 (RT+PCV), there was no difference in OS or PFS. OS at 2- and 5-yrs was 87% and 61% with RT alone versus (vs) 86% and 70% with RT+PCV (p=0.72). MOST was not reached in RT alone pts and was 6.0 yrs in RT+PCV pts. PFS at 2- and 5-yrs was 73% and 39% with RT alone vs 72% and 61% with RT+PCV (p=0.38). MPFST was 4.0 yrs with RT alone vs 6.0 yrs with RT+PCV. Acute grade 3–4 toxicity occurred in 9% of pts who received RT alone, 67% who received RT+PCV (mostly hematologic). There were no treatment deaths on either arm. Conclusions: 5-yr PFS was poor in all three arms ranging from 39% to 61%. Only half of favorable pts were disease-free at 5 yrs. In unfavorable pts, there was no OS advantage with the addition of PCV to RT. Both PFS and MPFST were better with the addition of PCV, but not significantly. Analysis of outcome by 1p19q status is pending.

No significant financial relationships to disclose.

Phase II trial of concomitant low dose temozolomide with external beam radiation (EBRT) followed by 12 months of temozolomide and irinotecan for newly diagnosed glioblastoma (GBM): Preliminary results of RTOG 04–20

1510

Background: Irinotecan and temozolomide compare favorably to regimens tested in recurrent GBM. RTOG 04–20 intensifies the Stupp R, et al. (N Engl J Med. 2005 Mar 10;352(10):987–96) adjuvant regimen, using irinotecan and temozolomide in place of temozolomide alone. Methods: Adult patients with newly diagnosed histologically confirmed, supratentorial GBM were eligible. Subjects began temozolomide 75mg/m2 daily the night before initiation of EBRT, and continued until the final day of RT. Pneumocystis prophylaxis was begun prior to RT and for 2 weeks following RT. Within 6 wks after EBRT, subjects with stable or improved MRI were scheduled to receive temozolomide 150mg/m2 on days 1–5, and irinotecan 200mg/m2 on days 1 and 15 of 28 day cycles × 12. Clinical assessments and post contrast MRI are required prior to EBRT, after RT, and after every 2 treatment cycles. Only nonenzyme inducing anticonvulsants were allowed. Results: Accrual of 170 patients was completed in September 2005 with 140 patients currently evaluable. Median age is 57yr, 80% were RPA class III or IV. Prior to cycle 1 of adjuvant therapy, 32 subjects withdrew (20 progressed, 4 toxicity). Of the first 25 subjects receiving irinotecan, 10 suffered grade 3–4 hematologic toxicities in the initial 3 cycles. The protocol was modified by dose reducing irinotecan to 100mg/m2 in cycle 1, escalating to 150 and 200mg/2 in subsequent cycles only if no dose limiting hematologic toxicity occured. No data is yet available on patients who started adjuvant therapy at the lower dose of irinotecan. Diarrhea and constitutional symptoms are the most common nonhematologic toxicies Conclusions: Irinotecan 200mg/m2 days 1 and 15 with temozolomide 150mg/m2 days 1–5 of 28 day cycles was well tolerated treating recurrent GBM, but this regimen was too myelosuppressive when given after concomitant low dose temozolomide and EBRT. Primary outcome data should be available in late 2006.

[Table: see text]

Validation of the RTOG recursive partitioning classification for head and neck tumors

BACKGROUND

We previously demonstrated that a mathematical technique called recursive partitioning analysis (RPA), when applied to the Radiation Therapy Oncology Group Head and Neck Cancer database, created rules that formed subgroups ("classes") having unique outcomes. We sought to learn if the application of RPA-derived rules to a new head and neck database would create classes that were similarly associated with outcome and thereby validate this technique.

METHODS

The rules derived from recursive partitioning analysis of the previous database were used to subgroup an independent, new head and neck cancer database (RTOG 85-27), created as part of a phase III trial of the hypoxic-cell radiosensitizer, Etanidazole. The resulting classes were compared with each other and with the classes formed from the previous database.

RESULTS

The rules derived by RPA from our previous database correctly grouped the tumors in the new database into unique classes of similar outcome. RPA could successfully use either survival or local-regional control of disease as the measure of outcome. As judged by comparison of the 95% confidence intervals, the outcome of the classes in the new database is essentially indistinguishable from the outcome of the classes in the previous database.

CONCLUSION

RPA-derived rules provide a reliable method to assort head and neck tumors into unique classes that are predictive of outcome. These rules can be successfully applied to new databases that were not used in the creation of the rules and thereby validate the methodology.

Outcomes of patients receiving radiation for carcinoma of the rectum. Results of the 1988-1989 patterns of care study

BACKGROUND

Clinical trials of surgical adjuvant treatment for patients with rectal carcinoma (RC) indicate that postoperative radiation therapy with concurrent chemotherapy (CRT) is superior to postoperative radiation alone (RT) or surgery alone. Whether preoperative treatment is superior to postoperative treatment is controversial. This Patterns of Care Study (PCS) surveyed patients with RC treated with radiation during the years 1988-1989 to determine the national practice standards and outcomes and to compare these results with those of clinical trials.

METHODS

A national survey of 73 institutions was conducted using 2-stage cluster sampling, and specific information on 406 patients with RC who received radiation at 69 facilities was collected. Follow-up information on 215 patients was subsequently collected by mail survey. There were no significant differences between the known prognostic indicators or treatment-related variables for patients for whom follow-up was available compared with the variables for patients for whom follow-up was not available. Follow-up ranged from 0 to 8.44 years with a median of 4 years. One hundred fifty-four patients (71%) received postoperative treatment, either RT (37%) or CRT (34%); and 40 (18%) received preoperative treatment, either RT (15%) or CRT (3%). Ninety-six patients (45%) received chemotherapy, and for 86% of those patients chemotherapy was administered concurrently with radiation.

RESULTS

Survival was stage-dependent (85% Stage I, 69% Stage II, and 54% Stage III at 5 years, P = 0.04). Survival was also substage-dependent, and patients with C(1) cancer had significantly higher 5-year survival than those with C(2)/C(3) cancer (89% vs. 48%, P = 0.008). Local failure was similar for Stage II and Stage III patients (10% vs. 11% at 5 years, respectively). In multivariate analyses, only stage and use of chemotherapy were significant to survival (Stage III vs. Stage I and II, relative risk [RR] = 2.52, and chemotherapy vs. no chemotherapy, RR = 0.46). A significantly higher 5-year survival rate was seen with postoperative CRT than with postoperative RT (69% vs. 50%, P = 0. 011). Preoperative radiation resulted in a significantly higher 5-year survival rate than postoperative radiation (85% vs. 50%, P = 0.0006), but not compared with postoperative CRT. Survival and local failure did not differ according to radiation therapy interruption or the interval between surgery and radiation.

CONCLUSIONS

Stage is an important prognostic indicator for survival, and among patients with Stage III malignancies survival in the substage C(1) is significantly higher than in the substages C(2) and C(3). As has been demonstrated in randomized trials, adjuvant postoperative CRT is superior to postoperative RT for patients with RC in this national study. These nationwide results of adjuvant treatment are comparable to those reported in randomized trials. The use of CRT was the only treatment-related factor that resulted in a significant reduction in the risk of death.

Outcomes of patients receiving radiation for carcinoma of the rectum. Results of the 1988-1989 patterns of care study

BACKGROUND

Clinical trials of surgical adjuvant treatment for patients with rectal carcinoma (RC) indicate that postoperative radiation therapy with concurrent chemotherapy (CRT) is superior to postoperative radiation alone (RT) or surgery alone. Whether preoperative treatment is superior to postoperative treatment is controversial. This Patterns of Care Study (PCS) surveyed patients with RC treated with radiation during the years 1988-1989 to determine the national practice standards and outcomes and to compare these results with those of clinical trials.

METHODS

A national survey of 73 institutions was conducted using 2-stage cluster sampling, and specific information on 406 patients with RC who received radiation at 69 facilities was collected. Follow-up information on 215 patients was subsequently collected by mail survey. There were no significant differences between the known prognostic indicators or treatment-related variables for patients for whom follow-up was available compared with the variables for patients for whom follow-up was not available. Follow-up ranged from 0 to 8.44 years with a median of 4 years. One hundred fifty-four patients (71%) received postoperative treatment, either RT (37%) or CRT (34%); and 40 (18%) received preoperative treatment, either RT (15%) or CRT (3%). Ninety-six patients (45%) received chemotherapy, and for 86% of those patients chemotherapy was administered concurrently with radiation.

RESULTS

Survival was stage-dependent (85% Stage I, 69% Stage II, and 54% Stage III at 5 years, P = 0.04). Survival was also substage-dependent, and patients with C(1) cancer had significantly higher 5-year survival than those with C(2)/C(3) cancer (89% vs. 48%, P = 0.008). Local failure was similar for Stage II and Stage III patients (10% vs. 11% at 5 years, respectively). In multivariate analyses, only stage and use of chemotherapy were significant to survival (Stage III vs. Stage I and II, relative risk [RR] = 2.52, and chemotherapy vs. no chemotherapy, RR = 0.46). A significantly higher 5-year survival rate was seen with postoperative CRT than with postoperative RT (69% vs. 50%, P = 0. 011). Preoperative radiation resulted in a significantly higher 5-year survival rate than postoperative radiation (85% vs. 50%, P = 0.0006), but not compared with postoperative CRT. Survival and local failure did not differ according to radiation therapy interruption or the interval between surgery and radiation.

CONCLUSIONS

Stage is an important prognostic indicator for survival, and among patients with Stage III malignancies survival in the substage C(1) is significantly higher than in the substages C(2) and C(3). As has been demonstrated in randomized trials, adjuvant postoperative CRT is superior to postoperative RT for patients with RC in this national study. These nationwide results of adjuvant treatment are comparable to those reported in randomized trials. The use of CRT was the only treatment-related factor that resulted in a significant reduction in the risk of death.

Anemia is associated with decreased survival and increased locoregional failure in patients with locally advanced head and neck carcinoma: a secondary analysis of RTOG 85-27

PURPOSE

The purpose of the present study is to investigate the strength of association between anemia and overall survival, locoregional failure, and late radiation therapy (RT) complications in a large prospective study of patients with advanced head and neck cancer treated with conventional radiotherapy with or without a hypoxic cell sensitizer.

METHODS AND MATERIALS

Between March 1988 and September 1991, 521 patients with Stage III or IV squamous cell carcinoma of the head and neck were entered into a randomized trial examining the addition of etanidazole (SR 2508) to conventional radiation therapy (RT) (66-74 Gy in 33-37 fractions, 5 days a week). Patients with hemoglobin (Hgb) levels measured and recorded prior to the second week of RT were included in this secondary analysis. Hemoglobin levels were stratified as normal (> or = 14.5 gm% for men, > or = 13 gm% for women) or anemic (< 14.5 gm% for men, < 13 gm% for women). Locoregional failure rates were calculated using the cumulative incidence approach. Overall survival was estimated according to the Kaplan-Meier method. Late RT toxicity was scored according to the RTOG morbidity scale. Differences in rates of overall survival, locoregional failure, and late complications were tested by the Cox proportional hazard model.

RESULTS

Of 504 eligible patients, 451 had a Hgb level measured and recorded prior to the second week of RT. One hundred sixty-two patients (35.9%) were considered to have a normal Hgb level and 289 patients (64.1%) were considered to be anemic. The estimated survival rate is 35.7% at 5 years in patients with a normal Hgb, versus 21.7% in anemic patients (p = 0.0016). The estimated locoregional failure rate is 51.6% at 5 years in patients with a normal Hgb, versus 67.8% in anemic patients (p = 0.00028). The estimated rate of grade 3 or greater toxicity is 19.8% at 5 years in patients with a normal Hgb, versus 12.7% in anemic patients (p = 0.063). On multivariate analysis, several variables were found to be independent predictors of survival including: T stage, Karnofsky performance status, N stage, age, total radiation dose to the primary, and Hgb level. Independent predictors of locoregional control included T stage, Karnofsky performance status, N stage, radiation dose, and Hgb level. The only variables which predicted for the development of late RT complications were gender (p = 0.0109) and age (p = 0.0167). These findings were consistent regardless of whether Hgb level was considered a dichotomous or continuous variable.

CONCLUSION

Low Hgb levels are associated with a statistically significant reduction in survival and an increase in locoregional failure in this large prospective study of patients with advanced head and neck cancer. Hgb level should be considered as a stratification variable in subsequent studies of head and neck cancer. Strategies to increase Hgb prior to RT in patients with head and neck cancer may lead to improved survival and loco-regional control.

Radiation therapy for rectosigmoid and rectal cancer: results of the 1992-1994 Patterns of Care process survey

PURPOSE

To determine the US national practice standards for patients with adenocarcinoma of the rectum treated in radiation oncology facilities.

MATERIALS AND METHODS

A national survey of 57 institutions identified 507 eligible patients who received radiation therapy as a component of their treatment for rectal cancer. A stratified two-stage cluster sampling with simple random sampling at each stage for each stratum was used and on-site surveys were performed.

RESULTS

Of the 507 patients, 378 (75%) received postoperative therapy, 110 (22%) received preoperative therapy, 17 (2%) received both preoperative and postoperative therapy, and less than 0.5% received intraoperative radiation alone. To more accurately assess the utilization of modern radiation techniques as well as recommendations of the National Cancer Institute (NCI)-sponsored, randomized, postoperative, adjuvant combined modality therapy rectal cancer trials into current practice, the analysis was limited to the 243 (48%) patients with tumor, node, and metastasis staging system classification T3 and/or N1-2M0 disease who underwent conventional surgery with negative margins. Although only 7% were treated on a clinical trial, 90% received chemotherapy for a median of 21 weeks. Most were treated with modern radiation treatment techniques. In contrast, techniques to identify and help exclude the small bowel from the radiation field were not routinely used.

CONCLUSION

Despite the fact that only 7% of patients with T3 and/or N1-2M0 disease were treated on a clinical trial, such trials appear to have resulted in a positive influence on the standard of practice within the oncology community. Although there are still some deficiencies, the majority of these patients received combined modality therapy and were treated with modern radiation therapy techniques.