Evidence in oncology. The Janeway lecture 2000

PURPOSE

The purpose of this address is to evaluate the types of evidence that have fashioned clinical decision making in oncology over the past century and to determine the appropriate weighting of evidence at the start of a new century in the shaping of patient care, clinical research, and health policy.

METHODS

Three separate analytic approaches were used: (1) a review of publications that altered medical practice, (2) a consideration of the misperception that little progress has been made by looking at the relationship between 5-year survival rates and national mortality rates, (3) an evaluation of the quality of data from clinical trials.

RESULTS

Published reports suggest that res ipsa loquitur was the dominant mindset of researchers in the first half century and continuing into the second half century. However, recognition of the scarcity of dramatic improvements in outcome and the possibility of incremental improvements led to the mounting of prospective randomized comparative trials that could identify such incremental improvements. Findings from these trials have profoundly altered patient care in the past quarter century. Data suggest that there is a sequence of events-increased survival rates in patients at research institutions followed by significant increases in survival rates nationally-followed by a reduction in annual mortality rates that do reflect improvements in treatment. Phase III comparative clinical trials yield the highest quality data in oncology. Meta-analysis of such data may be useful, but the most compelling data that alter medical practice come either from comparative clinical trials showing such significant differences in results as to necessitate their early termination on ethical grounds or from replicated phase III trials.

DISCUSSION

The nature of evidence influencing clinical practice and research has changed greatly in the past century. Although res ipsa loquitur still pervades the thinking of some oncologists, recognition of the incremental nature of progress is now the more dominant force in contemporary oncologic research. In addition, as molecular targets become the focus of therapeutic efforts, it will be especially important to proceed as quickly as possible to phase III comparative trials rather than to phase II studies.

Impact of involved field radiotherapy after CHOP-based chemotherapy on stage III-IV, intermediate grade and large-cell immunoblastic lymphomas

PURPOSE

To analyze the impact of involved field radiotherapy on local control, freedom from progression, and overall survival in patients with clinical Stage III-IV, intermediate grade, or large-cell immunoblastic lymphomas that responded to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-based induction chemotherapy.

METHODS AND MATERIALS

From July 1989 through October 1996, 32 patients with clinical Stage III and 27 patients with clinical Stage IV, intermediate grade, or large-cell immunoblastic lymphomas were prospectively enrolled on two protocols at The University of Texas M. D. Anderson Cancer Center. None had previously undergone treatment for lymphoma. The median patient age was 54 years (range: 26-85 years). There were a total of 172 involved sites of disease at presentation. All 59 patients received CHOP-based chemotherapy. At least six cycles of chemotherapy were delivered to 92% of the patients. Involved field radiotherapy (39.6-40.0 Gy in 20-22 fractions in 74% of cases) was administered to 28/59 (47%) patients beginning 3-4 weeks after chemotherapy. Sites were irradiated at the discretion of the treating physician. Irradiated and nonirradiated groups were compared in terms of maximum pre-chemotherapy tumor size and University of Texas M. D. Anderson Cancer Center tumor score. Kaplan-Meier estimates of local control per patient, freedom from progression, and overall survival for the irradiated and nonirradiated groups were calculated in terms of the stage of disease and treatment delivered. The resulting curves were compared using the log-rank test. The Cox proportional hazards model was used to assess the prognostic significance of tumor size, tumor score, treatment delivered, and stage.

RESULTS

The median length of follow-up for all patients was 53 months (range: 4-96 months). The median tumor size at the start of chemotherapy in irradiated patients was 4.5 cm (range: 0-15 cm) versus 3 cm (range: 0-7 cm) in nonirradiated patients (p = 0.004). The irradiated and nonirradiated groups were not significantly different in terms of tumor scores. Radiotherapy improved (p = 0.001) local control (5-year rates: 89% versus 52%) for Stages III and IV combined. This benefit was due to the dramatic improvement (p = 0.0009) in local control for patients with lymphomas measuring > or =4 cm at the start of chemotherapy (5-year rates: 89% for irradiated patients versus 33% for nonirradiated patients). Radiotherapy also improved (p = 0.003) freedom from progression (5-year rates: 85% for irradiated patients versus 51% for nonirradiated patients) for Stages III and IV combined. On multivariate analysis, radiotherapy was the most significant factor affecting local control and freedom from progression. Overall survival was not significantly different (p = 0. 620) between irradiated and nonirradiated patients (5-year rates: 87% versus 81%, respectively). When Stages III and IV were analyzed separately, radiotherapy improved local control and freedom from progression but not overall survival. Radiotherapy was tolerated reasonably well, with the main toxicity being moderate myelosuppression. Eleven out of 12 (92%) patients with recurrent disease at the time of their last follow-up visit were treated initially with chemotherapy alone.

CONCLUSION

Involved field radiotherapy improved local control and freedom from progression in patients with > or = 4 cm Stage III-IV, intermediate grade, or large-cell immunoblastic lymphomas that responded to CHOP-based induction chemotherapy. Involved field radiotherapy was tolerated reasonably well.

Agreement rates among single photon emission computed tomography using gallium-67, computed axial tomography and lymphangiography for Hodgkin disease and correlation of image findings with clinical outcome

BACKGROUND

This study was undertaken to systematically evaluate the agreement rates among single photon emission computed tomography using gallium-67 (Ga-67 SPECT), lymphangiography (LAG), and computed axial tomography (CT) scan findings for Hodgkin disease and to correlate radiologic findings with clinical outcome.

METHODS

One hundred three previously untreated patients with Hodgkin disease who had Ga-67 SPECT scan between August 1992 and December 1994 at our institution form the basis of this study. The agreement rates among Ga-67 SPECT, LAG, and CT scan findings were calculated by sites from the pretreatment evaluation throughout the courses of chemotherapy. The probabilities of recurrence or progression by sites were correlated with the radiologic findings.

RESULTS

The median follow-up was 3 years. The pretreatment agreement ranged from 75% to 100% between Ga-67 SPECT and CT scans, 85-100% between CT scan and LAG, and 74-99% between Ga-67 SPECT and LAG. A greater variation in agreement was observed once chemotherapy was started, the site with the least agreement being the mediastinum. The most common site of the recurrence or progression was also the mediastinum. When the CT scan showed persistent abnormality even after Ga-67 SPECT turned negative after chemotherapy, the chances of mediastinal recurrence or progression were 3 in 34 and 3 in 18 after 1-3 cycles and 4-6 cycles, respectively.

CONCLUSIONS

Although there was a relatively high correlation between Ga-67 SPECT and the other modalities, the intrinsic limitation of planar Ga-67 was still observed in Ga-67 SPECT especially in the mediastinum. There was still a moderate risk of mediastinal recurrence or progression even after residual CT scan abnormality lost gallium avidity from chemotherapy.

Mucosa-associated lymphoid tissue lymphoma with initial supradiaphragmatic presentation: natural history and patterns of disease progression

PURPOSE

Mucosa-associated lymphoid tissue (MALT) lymphoma commonly presents in the gastrointestinal (GI) tract. Supradiaphragmatic MALT lymphoma is less common and its natural history is not well defined. This study was conducted to understand the natural history, to determine the frequency of synchronous disease in the GI tract, and to understand the patterns of disease progression after treatment for supradiaphragmatic MALT lymphoma.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 39 patients who presented with supradiaphragmatic MALT lymphoma between 1991 and 1997.

RESULTS

The median age of patients was 58 years (range, 25-90 years) with 16 male and 23 female patients. The most common primary site was salivary gland followed by ocular adnexa, lung, oral cavity, and others. Sixteen patients underwent esophagogastroduodenoscopy and biopsy (EGD + Bx) and 4 were found to have gastric involvement. Ann Arbor stages were the following: IEA, 17; IIEA, 5, IIEB, 1; and IVA, 16. The initial treatments were: involved field radiation therapy (n = 10), chemotherapy (n = 14), combination of radiation therapy and chemotherapy (n = 9), observation after biopsy (n = 4), antibiotics only (n = 1), and patient refusal of further intervention (n = 1). Seven patients received antibiotics as a part of the initial treatment. Every patient except for 1 was alive at a median follow-up of 39.5 months (range, 3-83 months). Thirty-six patients achieved complete response (CR) to the initial treatment. The actuarial 5-year progression-free survival rate was 83%. Progression of the disease occurred in 4 patients, with 2 in the stomach. Salvage attempts were made to 4 and were successful in 3. Of the 2 patients who relapsed in the stomach, 1 had negative EGD + Bx at the time of initial diagnosis. An EGD + Bx was not done in the second patient.

CONCLUSION

Supradiaphragmatic MALT lymphoma appears to have a favorable prognosis. However, routine evaluation of the stomach is recommended for patients who present with supradiaphragmatic MALT lymphoma at the time of initial evaluation and at the time of relapse. Patients who failed initial therapy can be successfully salvaged with further treatment.

Outcome predictors for 143 patients with superior sulcus tumors treated by multidisciplinary approach at the University of Texas M. D. Anderson Cancer Center

PURPOSE

Superior sulcus tumors (SST) of the lung are uncommon and constitute approximately 3% of non-small cell lung cancer (NSCLC). These tumors cause specific symptoms and signs, and are associated with patterns of failure that differ from those seen for NSCLC tumors in other nonapical locations. Prognostic factors and most effective treatments are controversial. We conducted a retrospective study at The University of Texas M. D. Anderson Cancer Center to identify outcome predictors for patients with SST treated by a multidisciplinary approach.

METHODS AND MATERIALS

This retrospective review of 143 patients without distant metastasis at presentation is a continuation of a previous M. D. Anderson study now updated to 1994. In this study, we examine the 5-year survival rate by pretreatment tumor and patient characteristics and by the treatments received. Strict criteria were used to define SST. Actuarial life-table analyses and Cox proportional hazard models were used to compare survival rates.

RESULTS

Overall predictors of 5-year survival were weight loss (p < 0.01), supraclavicular fossa (p = 0. 03), or vertebral body (p = 0.05) involvement, stage of the disease (p < 0.01), and surgical treatment (p < 0.01). Five-year survival for patients with Stage IIB disease was 47% compared to 14% for Stage IIIA, and 16% for Stage IIIB. For patients with Stage IIB disease, surgical treatment (p < 0.01) and weight loss (p = 0.01) were significant independent predictors of 5-year survival. Among patients with Stage IIIA disease, the only predictor of survival was Karnofsky performance score (KPS) (p = 0.02). For patients with Stage IIIB disease, the only independent predictor of survival was a right superior sulcus location, which was associated with a worse 5-year survival rate than that for patients with tumors in the left superior sulcus (p = 0.02). More patients with adenocarcinoma than with squamous cell tumors experienced cerebral metastases within 5 years (p < 0.01). Patients without gross residual disease after surgical resection who received postoperative radiation therapy with total doses of 55 to 64 Gy had a 5-year survival rate of 82% as compared with the 5-year survival rate of 56% in patients who received 50 to 54 Gy. Twenty-three patients survived for longer than 3 years. Of these, 4 patients (17%) received radiation therapy alone or in combination with chemotherapy without surgical resection. The other 19 patients (83%) had resection combined with radiation therapy and/or chemotherapy.

CONCLUSIONS

The findings from this study confirm the importance of the new staging system, separating T3 N0 M0 (Stage IIB) from Stage IIIA, since there was a significant difference in the 5-year survival (p < 0.01). Interestingly, there was no significant 5-year survival difference between Stage IIIA (N2) and Stage IIIB (T4 or N3). This study also suggests that surgery is an important component of the multidisciplinary approach to patients with SST if their nodes were negative. Disease that is minimally invading surrounding normal structures can be resected followed by radiation therapy in doses of 55 to 64 Gy. Further investigation of treatment strategies combining high-dose radiation therapy (>/=66 Gy) with chemotherapy is indicated for patients with unresectable and/or node-positive (N2) SST.

Catalysis by metal-activated hydroxide in zinc and manganese metalloenzymes

The metal-activated hydroxide ion is a critical nucleophile in metalloenzymes that catalyze hydrolysis or hydration reactions. The most common metal used is zinc; occasionally, other transition metals such as manganese are required. Human carbonic anhydrase II and rat liver arginase serve as well-studied paradigms of zinc and manganese metalloenzymes, respectively. Comparative structure-function relationships between these two metalloenzymes highlight parallels in the chemistry of metal-activated hydroxide: (a) the protein environment of metal-bound hydroxide modulates its reactivity; (b) a hydrogen bond with metal-bound hydroxide holds it in the proper orientation for catalysis; (c) nonmetal substrate-binding sites are implicated in both enzyme mechanisms; and (d) regeneration of metal-bound hydroxide ion from a metal-bound water molecule requires proton transfer to bulk solvent mediated by a histidine proton shuttle residue. Interestingly, the electrostatics of catalysis differ between the two enzymes, in that the first step of catalysis requires formation of a negatively charged transition state in the carbonic anhydrase II mechanism, whereas a neutral transition state is approached in the arginase mechanism. This electrostatic feature may contribute to the differences in the chemistry, the metal binding sites, and the metal specificity between these two enzymes.

The outcome of combined-modality treatments for stage I and II primary large B-cell lymphoma of the mediastinum

PURPOSE

Primary mediastinal large B-cell lymphoma (PML) has clinicopathologic features distinct from those of other diffuse large-cell lymphomas. However, the optimal treatment for this tumor is evolving, and in particular, the role of radiation therapy remains undefined. We conducted a retrospective review to evaluate the role of radiation therapy in this disease.

METHODS AND MATERIALS

The medical records of 40 consecutive patients with Ann Arbor Stage I or II PML treated at our institution from January 1980 to December 1995 were reviewed. There were 18 patients with Stage I disease and 22 patients with Stage II disease; 62.5% were women and 37.5% were men. The median age was 32.4 years (range, 17-74 years). The tumor scores were 0 in 1 patient, I in 5 patients, II in 13 patients, III in 7 patients, IV in 4 patients, and unknown in 10 patients. The International Prognostic Index (IPI) was 0 in 10 patients, I in 26 patients, II in 2 patients, and unknown in 2 patients. All patients were treated with doxorubicin-based chemotherapy, and 35 patients received radiation therapy. For most patients who received radiation therapy, an involved field or a modified-mantle field was used, and a dose of 40 Gy in 20 fractions or 39.6 Gy in 22 fractions was administered. Univariate analysis was performed to identify prognostic factors.

RESULTS

The median follow-up in surviving patients was 56 months (range, 19-194 months). The actuarial 5-year relapse-free survival (RFS) rate and overall survival (OS) rate for all patients were 67% and 72%, respectively. Thirty-five patients achieved a complete response; 32 of these patients received radiation therapy. The patterns of failure for the complete responders were as follows: locoregional failure alone for 1 patient (at the margin of the radiation field); distant failure alone for 5 patients; and both locoregional (in-field) and distant failure for 1 patient. There were no failures after 2.5 years. None of the 5 patients who never achieved a complete response had local control, and all died with disease. Only 2 of the 5 completed the planned course of radiation therapy; both had massive mediastinal disease. There was no treatment-related death from the initial chemotherapy or radiation therapy. One patient developed a second malignancy (sarcoma) within the radiation field after 13 years. The tumor score was a significant predictor of RFS (p = 0.016) and OS (p = 0.006), but the IPI did not prove to be a significant predictor.

CONCLUSION

We recommend consolidative radiation therapy in view of the excellent local control and the lack of significant toxicity. Modified mantle or involved field appears to be an adequate volume, and 39.6-40 Gy appears to be an adequate dose. The tumor score is a significant prognostic factor.

Radiation Therapy Oncology Group (RTOG) trials for head and neck cancer

Clinical investigations for cancer of the head and neck, primarily tumors of the upper respiratory and digestive tracts, have been one of the most important components of the Radiation Therapy Oncology Group (RTOG) since its inception 30 years ago. Emphasis from the very beginning to the present time has been on altered fractionation. Studies of hypoxic cell sensitizers were also explored for many years. More recently, combinations of radiation therapy with cytotoxic chemotherapeutic agents, either sequentially or concurrently, have been a major focus. Although the majority of the trials have been for unresectable tumors, surgical adjuvant radiation therapy alone or combined with chemotherapy has also been an important activity. Combined modality trials emphasizing organ conservation have been carried out within the last decade. The RTOG represents a national and international resource for studies of cancer of the head and neck. Its results influence the care of patients and the clinical research environment.

Methodology and research by the Radiation Therapy Oncology Group (RTOG)

The studies of the Radiation Therapy Oncology Group have contributed important evidence to improve the outcome of patients with cancer. The evidence has been compelling both to the scientific community and to practicing physicians a very large number of whom participated in the investigations. It is a tribute to the hard work of these many hundred volunteers that the studies mentioned above, and many other clinical investigations were completed, and patients throughout the world had improved outcomes.

The management of superior sulcus tumors

Lung cancers arising from the extreme apex of the lung-superior sulcus tumors (SST)-have distinct symptoms and signs at presentation and a characteristic appearance on imaging. However, in their early stages, these tumors are often missed by traditional anterior/posterior chest X-rays. Recent advances in computed tomography (CT) and magnetic resonance imaging (MRI) have made selection of patients with potentially resectable of SST more accurate. If mediastinoscopy reveals no mediastinal lymph nodes involved, the patient can be treated with surgery followed by radiation therapy with or without chemotherapy. If mediastinoscopy reveals microscopic mediastinal lymph node involvement, the patient can be treated with induction radiation therapy and concurrent chemotherapy followed by surgery. If mediastinoscopy reveals gross mediastinal lymph node involvement (N2), or if CT reveals N3 or T4 lesions, the patient can be treated with concurrent chemotherapy and radiation therapy to relieve symptoms; the outcome of such treatment appears to be better than that of sequential chemotherapy followed by radiation therapy. Whenever possible, to enhance the patient's quality of life, surgery should be considered to improve function and relieve pain.

Recovery of sperm production following radiation therapy for Hodgkin's disease after induction chemotherapy with mitoxantrone, vincristine, vinblastine, and prednisone (NOVP)

PURPOSE

The effect on human male fertility of radiotherapy following chemotherapy for the treatment of Hodgkin's disease (HD) is unknown. The impact of radiation therapy, given after mitoxantrone, vincristine, vinblastine, and prednisone (NOVP) chemotherapy, on sperm production is the focus of this study.

PATIENTS

Serial semen analyses were performed on 34 patients with HD Stages I-III before NOVP chemotherapy, after chemotherapy prior to radiation, and after radiation therapy. The most inferior radiation portals for patients were: mantle, 1 patient; paraaortic-spleen, 3 patients; upper abdomen, 24 patients; abdominal spade, 4 patients; and pelvic, 2 patients. Testicular radiation dose measurements were available for 20 of these patients.

RESULTS

Before the start of radiation, 90% of patients were normospermic. The magnitude of the decline in sperm counts was related to the measured testicular dose and/or radiation fields employed. The minimum postradiotherapy counts, expressed as a fraction of pretreatment counts, for the various treatment groups are as follows: paraaortic-spleen, 20%; upper abdomen, testicular dose < 30 cGy, 4%; upper abdomen, testicular dose 30-39 cGy, 0.9%; abdominal spade, 0.02%; and pelvis, 0%. The time to nadir of sperm counts averaged 4.5 months. Recovery to normospermic levels occurred in 96% of patients, with most recovering to that level within 18 months.

CONCLUSION

The effect of radiation following NOVP chemotherapy on sperm counts was no greater than would be expected with radiation therapy alone. In most patients, sperm counts recovered to levels compatible with normal fertility.

Three-dimensional treatment planning for central lymphatic irradiation

The purpose of this study was to investigate the applicability of 3-dimensional (3D) treatment planning for central lymphatic irradiation (CLI). CLI requires more than 1 course of treatment with large, highly blocked, overlapping beams, and careful planning is required to ensure that such treatments are delivered safely and effectively. Three patients were selected for this study. Each patient completed at least 1 course of radiation therapy for CLI and was scheduled to receive irradiation to an adjacent area with overlapping beams. Two treatment plans were generated for each patient: a standard, 2-dimensional (2D) treatment plan and a 3D treatment plan designed to mimic the standard plan, taking advantage of unique 3D features. The time required to complete the treatment plans and differences in the treatment planning processes were noted. The time required to generate a 3D treatment plan was approximately the same as the time required to generate a standard 2D treatment plan; however, the 3D planning process required less redundancy of data entry than the 2D process. The 3D treatment plan was qualitatively similar to the standard 2D treatment plan; however, differences in beam penumbra and beam junctions were noted, and are most likely due to differences in the dose-calculation models used in these 2 treatment planning systems. Dose-volume histograms (DVHs) were calculated for the spinal cord and were found to be useful to the physicians for quickly and accurately evaluating the presence or absence of hot spots in the junction region. 3D treatment-planning has some advantages over 2D treatment planning for CLI; the main advantage of the 3D treatment plan is that it provides a single plan for each patient with multiple views of the data, including different planar cross-sections and DVHs. For the 2D system, a separate plan was generated for each view, requiring redundant data entry. The quality of the output of the 3D treatment plans is superior to that of 2D treatment plans, but the clinical utility is about the same. Currently, the time required for 2D and 3D treatment plans is similar. However, as dosimetrists become more familiar with 3D treatment planning systems, we expect this familiarity and regularity of use to translate into a significant time advantage.

Preliminary report of toxicity following 3D radiation therapy for prostate cancer on 3DOG/RTOG 9406

PURPOSE

A prospective Phase I dose escalation study was conducted to determine the maximally-tolerated radiation dose in men treated with three-dimensional conformal radiation therapy (3D CRT) for localized prostate cancer. This is a preliminary report of toxicity encountered on the 3DOG/RTOG 9406 study.

METHODS AND MATERIALS

Each participating institution was required to implement data exchange with the RTOG 3D quality assurance (QA) center at Washington University in St. Louis. 3D CRT capabilities were strictly defined within the study protocol. Patients were registered according to three stratification groups: Group 1 patients had clinically organ-confined disease (T1,2) with a calculated risk of seminal vesicle invasion of < 15%. Group 2 patients had clinical T1,2 disease with risk of SV invasion > or = 15%. Group 3 (G3) patients had clinical local extension of tumor beyond the prostate capsule (T3). All patients were treated with 3D techniques with minimum doses prescribed to the planning target volume (PTV). The PTV margins were 5-10 mm around the prostate for patients in Group 1 and 5-10 mm around the prostate and SV for Group 2. After 55.8 Gy, the PTV was reduced in Group 2 patients to 5-10 mm around the prostate only. Minimum prescription dose began at 68.4 Gy (level I) and was escalated to 73.8 Gy (level II) and subsequently to 79.2 Gy (level III). This report describes the acute and late toxicity encountered in Group 1 and 2 patients treated to the first two study dose levels. Data from RTOG 7506 and 7706 allowed calculation of the expected probability of observing a > or = grade 3 late effect more than 120 days after the start of treatment. RTOG toxicity scores were used.

RESULTS

Between August 23, 1994 and July 2, 1997, 304 Group 1 and 2 cases were registered; 288 cases were analyzable for toxicity. Acute toxicity was low, with 53-54% of Group 1 patients having either no or grade 1 toxicity at dose levels I and II, respectively. Sixty-two percent of Group 2 patients had either none or grade 1 toxicity at either dose level. Few patients (0-3%) experienced a grade 3 acute bowel or bladder toxicity, and there were no grade 4 or 5 toxicities. Late toxicity was very low in all patient groups. The majority (81-85%) had either no or mild grade 1 late toxicity at dose level I and II, respectively. A single late grade 3 bladder toxicity in a Group 2 patient treated to dose level II was recorded. There were no grade 4 or 5 late effects in any patient. Compared to historical RTOG controls (studies 7506, 7706) at dose level I, no grade 3 or greater late effects were observed in Group 1 and Group 2 patients when 9.1 and 4.8 events were expected (p = 0.003 and p = 0.028), respectively. At dose level II, there were no grade 3 or greater toxicities in Group 1 patients and a single grade 3 toxicity in a Group 2 patient when 12.1 and 13.0 were expected (p = 0.0005 and p = 0.0003), respectively. Multivariate analysis demonstrated that the relative risk of developing acute bladder toxicity was 2.13 if the percentage of the bladder receiving > or = 65 Gy was more than 30% (p = 0.013) and 2.01 if patients received neoadjuvant hormonal therapy (p = 0.018). The relative risk of developing late bladder complications also increased as the percentage of the bladder receiving > or = 65 Gy increased (p = 0.026). Unexpectedly, there was a lower risk of late bladder complications as the mean dose to the bladder and prescription dose level increased. This probably reflects improvement in conformal techniques as the study matured. There was a 2.1 relative risk of developing a late bowel complication if the total rectal volume on the planning CT scan exceeded 100 cc (p = 0.019).

CONCLUSION

Tolerance to high-dose 3D CRT has been better than expected in this dose escalation trial for Stage T1,2 prostate cancer compared to low-dose RTOG historical experience. With strict quality assurance standards and review, 3D CRT can be safely studied in a co

Salvage central lymphatic irradiation in follicular lymphomas following failure of chemotherapy: a feasibility study

PURPOSE

Management of follicular lymphoma after chemotherapy failure has been controversial and has ranged from watchful waiting to high-dose chemotherapy. High-dose chemotherapy with bone marrow reconstitution may produce clinical and molecular complete responses at the risk of serious morbidity and mortality. It has been previously reported that central lymphatic irradiation (CLI) can achieve long-term relapse-free survival in patients with Stage I, II, or III follicular lymphoma. Therefore, we investigated the feasibility of treating patients in whom front-line chemotherapy failed with salvage CLI instead of instituting more intensive chemotherapy.

METHODS AND MATERIALS

Salvage CLI with curative intent for patients with follicular lymphoma was started at The University of Texas M. D. Anderson Cancer Center in 1992. Eleven patients whose disease showed poor response to or relapsed after chemotherapy were managed with this approach. The median age of the patients was 61 years. Criteria for exclusion included bone marrow involvement or other evidence of Ann Arbor Stage IV disease at any time during the course of the disease. Overall survival and relapse-free survival were calculated from the first day of CLI.

RESULTS

Ten patients were alive at a median follow-up of 25 months (range 9-73 months). The treatment was well tolerated in general. Two patients could not complete CLI: one 75-year-old patient owing to prolonged platelet count depression and deterioration in general medical condition, and a 66-year-old patient because of exacerbation of preexisting pancytopenia and worsening of heart disease. Everyone who completed CLI remains in remission at the time of this report, except for one patient who had a relapse in the right lacrimal gland at 32 months. This patient was treated with local radiation therapy and is free of disease. Eventual recovery of the blood counts was observed for the patients who completed CLI.

CONCLUSION

These results demonstrate for the first time that with CLI, it is possible to achieve complete remission of acceptable quality in follicular lymphoma patients who experience a chemotherapy failure. The main toxicity is limited to transient depression in hematological profiles. The treatment is fairly well tolerated and seems to carry little risk compared with high-dose chemotherapy and bone marrow rescue. Salvage CLI may not necessarily compromise future treatment with chemotherapy, including autologous bone marrow or stem cell transplantation, because the patients' blood counts recover.

Arginase-boronic acid complex highlights a physiological role in erectile function

The crystal structure of the complex between the binuclear manganese metalloenzyme arginase and the boronic acid analog of L-arginine, 2(S)-amino-6-boronohexanoic acid (ABH), has been determined at 1.7 A resolution from a crystal perfectly twinned by hemihedry. ABH binds as the tetrahedral boronate anion, with one hydroxyl oxygen symmetrically bridging the binuclear manganese cluster and a second hydroxyl oxygen coordinating to Mn2+A. This binding mode mimics the transition state of a metal-activated hydroxide mechanism. This transition state structure differs from that occurring in NO biosynthesis, thereby explaining why ABH does not inhibit NO synthase. We also show that arginase activity is present in the penis. Accordingly, the tight binding and specificity of ABH allows us to probe the physiological role of arginase in modulating the NO-dependent smooth muscle relaxation required for erection. Strikingly, ABH causes significant enhancement of nonadrenergic, noncholinergic nerve-mediated relaxation of penile corpus cavernosum smooth muscle, suggesting that arginase inhibition sustains L-arginine concentrations for NO synthase activity. Therefore, human penile arginase is a potential target for therapeutic intervention in the treatment of erectile dysfunction.

Clinical course of solitary extramedullary plasmacytoma

BACKGROUND AND PURPOSE

Solitary extramedullary plasmacytoma (EMP) represents a rare category of malignant disease on which there are limited data in regard to diagnosis, staging and natural history. This study attempted to clarify the clinical course of solitary extramedullary plasmacytoma after radiation or surgical therapy given with curative intent.

MATERIALS AND METHODS

The diagnosis was based on a mass of clonal plasma cells separate from bone or bone marrow without evidence of occult disease elsewhere. Between 1963 and 1996, 22 previously untreated patients with an EMP were diagnosed. Disease presented in the head or neck in 86%, usually in the nasal cavity (NC) or maxillary sinus (MS), and in these areas local bone destruction was found in 10 of 11 patients. Among all patients, serum myeloma protein was present in three patients (14%) and Bence Jones protein alone was found in two patients (9%). Radiation therapy was the sole treatment for 18 of 22 patients, and the median radiotherapy dose was 50 Gy (range, 40-60 Gy); five of seven patients with an EMP of oral cavity (OC), oropharynx (OP), nasopharynx (NP), parotid or larynx also received elective neck irradiation. Two patients underwent surgery plus postoperative irradiation of a plasmacytoma of the sigmoid colon or pleura, and two patients had resection alone of a plasmacytoma of the colon or cervical lymph node.

RESULTS

Local control was achieved in 21 of 22 patients (95%), and disease never recurred in regional nodes. Disappearance of myeloma protein occurred in three of five patients with an evaluable abnormality. Multiple myeloma developed in seven patients (32%), all within 5 years. The 5-year rate of freedom from progression to multiple myeloma was 56% and the median survival was 9.5 years.

CONCLUSION

Radiation therapy achieved excellent locoregional control of EMP with an approximate cure fraction of 50%.

Is prolonged survival possible for patients with supraclavicular node metastases in non-small cell lung cancer treated with chemoradiotherapy?: Analysis of the Radiation Therapy Oncology Group experience

PURPOSE

To determine if patients with non-small cell lung carcinoma (NSCLC) and positive supraclavicular nodes (SN+) have a similar outcome to other patients with Stage IIIB NSCLC (SN-) when treated with modern chemoradiotherapy.

METHODS AND MATERIALS

Using the Radiation Therapy Oncology Group (RTOG) database, data were retrospectively analyzed from five RTOG trials studying chemoradiotherapy for NSCLC: 88-04, 88-08 (chemo-RT arm), 90-15, 91-06, 92-04. Comparisons were made between the SN+ and SN- subgroups with respect to overall survival, progression-free survival (PFS), and metastases-free survival (MFS) using the log rank test. Cox multivariate proportional hazards regression analysis was used to determine the effect of several potential confounding variables, including histology (squamous vs. nonsquamous), age (>60 vs. < or = 60), Karnofsky Performance Status (KPS) (<90 vs. > or = 90), weight loss (> or = 5% vs. <5%), and gender.

RESULTS

A total of 256 Stage IIIB patients were identified, of whom 47 had supraclavicular nodes (SN+) and 209 did not (SN-). Statistically significantly more SN+ patients had nonsquamous histology (p = 0.05); otherwise, known prognostic factors were well balanced. The median survival for SN+ patients was 16.2 months, vs. 15.6 months for SN- patients. The 4-year actuarial survival rates were 21% and 16% for SN+ and SN- patients respectively (p = 0.44). There was no statistically significant difference in the 4-year PFS rates (19% vs. 14%, p = 0.48). The Cox analysis did not show the presence or absence of supraclavicular nodal disease to be a prognostic factor for survival, MFS, or PFS. The only statistically significant factor on multivariate analysis was gender, with males having a 40% greater risk of mortality than females (p = 0.03). There were no clinically significant differences in toxicity when comparing SN+ vs. SN- patients. Among the 47 SN+ patients, there were no reported cases of brachial plexopathy or other > or = Grade 2 late neurologic toxicity.

CONCLUSIONS

When treated with modern chemoradiotherapy, the outcome for patients with supraclavicular metastases appears to be similar to that of other Stage IIIB patients. SN+ patients should continue to be enrolled in trials studying aggressive chemoradiotherapy regimens for locally advanced NSCLC.

Consensus statements on radiation therapy of prostate cancer: guidelines for prostate re-biopsy after radiation and for radiation therapy with rising prostate-specific antigen levels after radical prostatectomy. American Society for Therapeutic Radiology and Oncology Consensus Panel

PURPOSE

To develop evidence-based guidelines for (1) prostate re-biopsy after radiation and (2) radiation therapy with rising prostate-specific antigen (PSA) levels after radical prostatectomy in the management of patients with localized prostatic cancer.

DESIGN

The American Society of Therapeutic Radiology and Oncology (ASTRO) challenged a multidisciplinary consensus panel to address consensus on specific issues in each of the two topics. Four well-analyzed patient data sets were presented for review and questioning by the panel. The panel sought criteria that would be valid for patients in standard clinical practice as well as for patients enrolled in clinical trials. Subsequent to an executive session that followed these presentations, the panel presented its consensus guidelines.

RESULTS AND CONCLUSIONS

Based on the data presented, the prostate re-biopsy negative rates ranged from 62% to 80% for patients with stage T1-2 tumors. The panel judged that prostate re-biopsy is not necessary as standard follow-up care and that the absence of a rising PSA level after radiation therapy is the most rigorous end point of total tumor eradication. Further, the panel judged that re-biopsy may be an important research tool. Based on the data presented, the long-term (5 years or more) PSA remission rate after salvage radiation therapy ranges from 27% to 45%. The panel requested results from prospective randomized trials to evaluate optimally this information. The panel judged that the total dose of radiation should be 64 Gy or slightly higher and that, in patients with or without radiation therapy, there is no standard role for androgen suppressant therapy for rising PSA values after prostatectomy.

Primary non-Hodgkin lymphoma of the small bowel

PURPOSE

To clarify the natural history of primary lymphoma of the small bowel and identify preferred treatments for it.

MATERIALS AND METHODS

A retrospective analysis of 61 patients with primary lymphoma of the small bowel was performed. The Ann Arbor stages were I in 20 patients, II in 28, and IV in 13. After resection or biopsy, 15 patients were treated with radiation therapy, 26 with chemotherapy, and 16 with combined-modality therapy. Four patients underwent no adjuvant treatment after resection.

RESULTS

The actuarial 10-year overall survival and relapse-free survival for the patients with intermediate- and high-grade lymphoma were 47% and 53%, respectively. For the patients with low-grade lymphoma, these rates were 81% and 62%. For patients who underwent radiation therapy, combined-modality therapy, or chemotherapy, the recurrence rates inside the abdomen or pelvis were one of 12, two of 15, and five of 20, respectively, and those outside the abdomen or pelvis were four of 12, one of 15, and zero of 20, respectively. Four of the five abdominopelvic recurrences of disease in the chemotherapy group were among the nine patients who had Ann Arbor stage II disease.

CONCLUSION

Chemotherapy lowered the recurrence rate outside the abdomen or pelvis. Patients with stage II disease may benefit most from radiation therapy.

Apoptosis and the Bcl-2 gene family -- patterns of expression and prognostic value in stage I and II follicular center lymphoma

PURPOSE

The prognostic significance of spontaneous levels of apoptosis and Bcl-2, Bax, and Bcl-x protein expression in follicular center lymphoma (FCL) is unknown. The objectives of this retrospective study were (1) to investigate the relationship between pretreatment apoptosis levels and long-term treatment outcome in patients with Stage I and II FCL; (2) to define the incidence and patterns of Bax and Bcl-x protein expression in human FC; and (3) to determine the relationship of Bcl-2, Bax, and Bcl-x expression with spontaneous apoptosis levels and clinical outcome in localized FCL.

METHODS AND MATERIALS

Between 1974 and 1988, 144 patients with Stage I or II FCL were treated. Hematoxylin and eosin (H & E) stained tissue sections of pretreatment specimens were retrieved for 96 patients. Treatment consisted of regional radiation therapy (XRT) for 25 patients, combined modality therapy (CMT) consisting of combination chemotherapy and XRT for 57 patients, and other treatments for 14 patients. Median follow-up for living patients was nearly 12 years. The apoptotic index (AI) was calculated by dividing the number of apoptotic cells by the total number of cells counted and multiplying by 100. Expression of Bcl-2, Bax, and Bcl-x proteins was assessed using immunohistochemistry.

RESULTS

The mean and median AI values for the entire group were 0.53 and 0.4, respectively (range: 0-5.2). The AI strongly correlated with cytologic grade, with mean AI values of 0.25 for grade 1, 0.56 for grade 2, and 0.84 for grade 3 (p < 0.0005; Kendall correlation). A positive correlation was present between grouped AI and grouped mitotic index (MI) (p = 0.014). For patients treated with CMT, an AI < 0.4 correlated with improved freedom from relapse (FFR) p = 0.0145) and overall survival (OS) (p = 0.0081). An AI < 0.4 did not correlate with clinical outcome for the entire cohort or for patients receiving XRT only. Staining of tumor follicles for the Bcl-2 protein was positive, variable, and negative in 73%, 15%, and 12% of cases, respectively. Positive staining of tumor follicles was observed in 96% of cases for both the Bax and Bcl-x proteins. Expression of Bcl-2, Bax, or Bcl-x did not correlate with AI or clinical outcome.

CONCLUSION

The level of spontaneous apoptosis in pretreatment specimens correlates with cytologic grade of FCL and is a significant predictor of FFR and OS for patients with localized FCL receiving CMT.

Role of radiation therapy to the brain in leukemic patients with cranial nerve palsies in the absence of radiological findings

The value of brain radiotherapy for leukemic patients with cranial nerve palsies in the absence of radiological evidence of leukemic infiltration is not well defined. This retrospective study was undertaken to evaluate the effectiveness of brain irradiation in reversing the cranial nerve palsies in leukemic patients with no radiological evidence of intracranial leukemic infiltration. Records of leukemic patients who received brain radiotherapy between June 1980 and December 1993 were reviewed. Criteria for inclusion were 1) no evidence of intracranial leukemic infiltration by computed axial tomography (CT) or magnetic resonance imaging scan (MRI), 2) no evidence of leukemic infiltration on ophthalmologic examination, and 3) no previous radiotherapy to the brain. Actuarial survival rates were calculated using the Kaplan-Meier method. Pearson's chi-squared test was used to compare responses. Twenty-eight patients met these criteria. The median age was 38 years (range 3-75 years): Seventeen patients had acute lymphoblastic leukemia, nine had acute myelogenous leukemia, and two had chronic myelogenous leukemia. Four patients had initial presentation with leukemia, and 24 presented with relapse. Twenty-six patients had cerebrospinal fluid cytology that was positive for leukemic cells. Fifteen patients had involvement of more than one cranial nerve, and nine had bilateral involvement. The most commonly involved nerves were the facial (n = 18), oculomotor (n = 9), and abducens nerves (n = 8). Twenty-six patients received whole-brain radiotherapy. Two received radiation to the base of the skull only. The median radiation dose was 24 Gy (range 16-30 Gy) at 2-3 Gy per fraction. Every patient had either concomitant intrathecal (n = 6) or systemic (n = 5) chemotherapy or both (n = 17) with radiation. Fourteen patients had complete reversal of the cranial nerve deficit, eight had partial recovery, and four had no response or progression of the disease. The response was unknown in two patients. Factors associated with complete response were unilateral versus bilateral involvement (72% vs. 13%, P = 0.005) and single versus multiple nerve involvement (75% vs. 36%, P = 0.045). In conclusion, radiation therapy to whole brain was effective in reversing cranial nerve deficits from leukemia, although the leukemic infiltration may not be visualized by CT or MRI. No dose-response relationship was observed in the range we examined.

Stages I-III follicular lymphoma: role of CT of the abdomen and pelvis in follow-up studies

PURPOSE

To evaluate the efficiency of axial computed tomography (CT) in detecting relapses of stage I, II, or III follicular lymphoma.

MATERIALS AND METHODS

A total of 328 patients with previously untreated stage I, II, or III follicular lymphoma were treated between 1978 and 1994. Two hundred fifty-seven patients achieved complete response; 78 who relapsed form the basis of this study. Fifteen patients had stage I; 28, stage II; and 35, stage III disease. Fifteen patients underwent radiation therapy; 12, chemotherapy; and 51, radiation and chemotherapy. Medical records were reviewed to analyze the yield of abdominal and pelvic CT in detecting recurrence relative to the yield of standard clinical, hematologic, and imaging studies. A positive study was defined as one that led to or was abnormal at the diagnosis of recurrence.

RESULTS

The median follow-up was 101 months. Eleven relapses were detected only at abdominal, pelvic, or both abdominal and pelvic CT.

CONCLUSION

Fourteen percent (11 of 78) of the relapses were detected solely at abdominal and/or pelvic CT. Eleven (4.3%) of the 257 patients who achieved complete response benefited from abdominal and pelvic CT. The yield of the routine use of abdominal and pelvic CT in follow-up studies appears to be low for stages I-III follicular lymphoma.