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Biomedical subjects

M J John

Publications and source records attributed to M J John.

At least 19 recordsLinked to original sources
PubMed2003

Hyperbaric oxygen therapy: current trends and applications.

Hyperbaric medicine is the fascinating use of barometric pressure for delivering increased oxygen dissolved in plasma to body tissues. Hyperbaric oxygen therapy (HOT) or hyperbaric oxygen (HBO) involves intermittent inhalation of 100% oxygen under a pressure exceeding that of the atmosphere, that is greater than 1 atmosphere absolute (ATA). Therapy is given in special therapeutic chambers which were earlier used primarily to treat illnesses of deep sea divers. There is recently a renewed interest in this field all over the world. Acute traumatic wounds, crush injuries, burns, gas gangrene and compartment syndrome are indications where addition of hyperbaric oxygen may be life and limb saving. Patients who are suffering with non-healing ulcers, decubitus ulcers (bed sores) and all late sequelae of radiation therapy are also benefited with HBO therapy. Acute hearing loss and many neurological illnesses are also now known to possibly benefit from hyperbaric oxygen therapy. This article aims to give a brief overview of the rationale, existing trends and applications of this therapy.

Humans↗
PubMed2001

Phase III radiation therapy oncology group (RTOG) trial 86-10 of androgen deprivation adjuvant to definitive radiotherapy in locally advanced carcinoma of the prostate.

PURPOSE: To test the hypothesis that androgen ablation before and during radiotherapy for locally advanced carcinoma of the prostate may, by reducing tumor bulk and enhancing tumor cell kill, improve locoregional control and ultimately survival. METHODS AND MATERIALS: The study was conducted from 1987 to 1991. Eligible patients were those with bulky tumors (T2--T4) with or without pelvic lymph node involvement and without evidence of distant metastases. They were randomized to receive goserelin, 3.6 mg every 4 weeks; and flutamide, 250 mg t.i.d. for 2 months before radiation therapy and during radiation therapy (Arm I), or radiation therapy alone (Arm II). Of 471 randomized patients, 456 were evaluable: 226 on Arm I and 230 on Arm II. RESULTS: As of November 1999, the median follow-up has reached 6.7 years for all patients and 8.6 years for alive patients. At 8 years, androgen ablation has been associated with an improvement in local control (42% vs. 30%, p = 0.016), reduction in the incidence of distant metastases (34% vs. 45%, p = 0.04), disease-free survival (33% vs. 21%, p = 0.004), biochemical disease-free survival = PSA <1.5 (24% vs. 10%, p < 0.0001), and cause-specific mortality (23% vs. 31%, p = 0.05). However, subset analysis indicates that the beneficial effect of short-term androgen ablation appears preferentially in patients with Gleason score 2--6. In that population, there is a highly significant improvement in all endpoints, including survival (70% vs. 52%, p = 0.015). In patients with Gleason 7--10 tumors, the regimen has not resulted in a significant enhancement in either locoregional control or survival. CONCLUSION: In patients with Gleason score 2--6 carcinoma of the prostate, a short course of androgen ablation administered before and during radiotherapy has been associated with a highly significant improvement in local control, reduction in disease progression, and overall survival.

Adenocarcinoma↗
PubMed2000

Outcome of patients receiving radiation for cancer of the esophagus: results of the 1992-1994 Patterns of Care Study.

PURPOSE: A Patterns of Care Study examined the records of patients with esophageal cancer (EC) treated with radiation in 1992 through 1994 to determine the national practice processes of care and outcomes and to compare the results with those of clinical trials. PATIENTS AND METHODS: A national survey of 63 institutions was conducted using two-stage cluster sampling, and specific information was collected on 400 patients with squamous cell (62%) or adenocarcinoma (37%) of the thoracic esophagus who received radiation therapy (RT) as part of primary or adjuvant treatment. Patients were staged according to a modified 1983 American Joint Committee on Cancer staging system. Fifteen percent of patients had clinical stage (CS) I disease, 40% had CS II disease, and 30% had CS III disease. Twenty-six percent of patients underwent esophagectomy. Seventy-five percent of patients received chemotherapy; 84% of these received concurrent chemotherapy and radiation (CRT). RESULTS: Significant variables for overall survival in multivariate analysis include the use of esophagectomy (risk ratio [RR] = 0.62), the use of chemotherapy (RR = 0.63), Karnofsky performance status (KPS) greater than 80 (RR = 0.61), CS I or II disease (RR = 0.66), and facility type (RR = 0.72). Age, sex, and histology were not significant. Preoperative CRT resulted in a nonsignificantly higher 2-year survival rate compared with definitive CRT alone (63% v 39%; P =.11), whereas 2-year survival by planned treatment rather than treatment given was 47.7% for preoperative CRT and 35.4% for definitive CRT (P =.23). Definitive CRT compared with definitive RT alone resulted in significantly higher 2-year survival (39% v 20.6%; P =.027) and lower 2-year local regional failure (30% v 57.9%; P =. 0031). CONCLUSION: This study confirms the value of CRT in EC treatment. It indicates that the results obtained in practice settings nationwide are similar to those obtained in clinical trials and that KPS and the 1983 clinical staging system are useful prognostic indicators. The suggested value of esophagectomy and superiority of preoperative CRT over CRT alone in this study should be tested in a randomized trial.

Adenocarcinoma↗
PubMed1999

The evaluation and treatment of patients receiving radiation therapy for carcinoma of the esophagus: results of the 1992-1994 Patterns of Care Study.

BACKGROUND: For the first time, a Patterns of Care Study (PCS) was conducted in 1992-1994 to determine the national practice standards in evaluating and treating patients with esophageal carcinoma and to determine the degree to which clinical trials have been incorporated into national practice. METHODS: A national survey of 61 institutions using 2-stage cluster sampling was conducted, and specific information was collected on 400 patients with squamous cell carcinoma or adenocarcinoma of the thoracic esophagus who received radiation therapy (RT) as part of definitive or adjuvant management of their disease. Patients were staged according to a modified 1983 American Joint Committee on Cancer staging system. Chi-square tests for significant differences between academic and nonacademic institutions for a particular variable were performed. RESULTS: The median age of patients was 66.7 years (range, 26-89 years); 76.5% were male and 23.5% were female. Karnofsky performance status was > or = 80 for 88.3% of patients. Squamous cell carcinoma was diagnosed in 61.5% and adenocarcinoma in 36.8%. Fifteen percent were Clinical Stage (CS) I, 39.5% CS II, and 29.5% CS III. Evaluative procedures included endoscopy (>93%), computed tomography (CT) of the chest (86%), CT of the abdomen (75%), esophagography (68.5%), and endoscopic ultrasound (3.5%). Endoscopic ultrasound and CT of the chest were performed significantly more frequently at academic than nonacademic facilities (6.1% vs. 1.0% and 91.9% vs. 81.3%, respectively). Three-quarters of all patients received chemotherapy and RT and 62.5% received concurrent chemotherapy and RT as part of their treatment. Treatments included chemotherapy plus RT (54.0%), RT alone (20.3%), preoperative chemotherapy + RT (13.3%), postoperative chemotherapy + RT (7.7%), postoperative RT (3.5%), and preoperative RT (1.2%). The chemotherapeutic agents most frequently used were 5-fluorouracil (84%), cisplatin (64%), and mitomycin (9%); academic instututions used cisplatin significantly more often and mitomycin significantly less often than nonacademic institutions. Brachytherapy was used in 8.5% of cases. The median total dose of external beam radiation was 50.4 gray and the median dose per fraction was 1.8 gray. CONCLUSIONS: This study establishes the national benchmarks for the evaluation and treatment of patients with esophageal carcinoma at radiation facilities in the U.S. It also indicates that the majority of patients given RT as a component of treatment for esophageal carcinoma receive chemoradiation rather than RT alone, as supported by clinical trials. Although some differences in the evaluation of esophageal carcinoma were noted between academic and nonacademic facilities, there was no difference in the frequency of use of chemoradiation versus RT by facility type.

Adenocarcinoma↗
PubMed1995

Phase II trial of hormonal cytoreduction with megestrol and diethylstilbestrol in conjunction with radiotherapy for carcinoma of the prostate: outcome results of RTOG 83-07.

PURPOSE: RTOG 83-07 is a Phase II randomized protocol designed to compare the efficacy and toxicity of Megestrol vs. Diethylstilbestrol (DES) used as cytoreductive agents prior to and during radiotherapy. The end points of this study include tumor clearance rate, effect on serum testosterone, loco-regional control, disease-free interval, and survival. METHODS AND MATERIALS: Eligible patients were those with histologically confirmed locally advanced adenocarcinoma, clinical Stage B2 (T2B) and C (T3) without regional lymph node involvement, or with lymph node involvement limited to the pelvis. Patients were stratified by clinical stage, histological grade, and nodal status, and were randomized to receive either Megestrol 40 mg three times per day by mouth, or Diethylstilbestrol 1 mg three times per day by mouth. The drugs were started 2 months prior to initiation of radiotherapy and were continued throughout the radiotherapy course. Radiotherapy consisted of 44-46 Gy, 1.8-2 Gy per day to the regional lymphatics, followed by a boost to the prostate consisting of 20-25 Gy, 1.8-2 Gy per day, to a total of 65-70 Gy. Serum testosterone levels were recorded throughout the treatment course. Tumor response was assessed clinically and radiographically (CT scan). From March 1983 through June 1986 a total of 203 patients were accessioned to the study; 198 were analyzable. RESULTS: Correlation of the incidence of drug-related toxicity and treatment arm assignment revealed a significantly higher incidence of complications in the Diethylstilbestrol (DES) arm. The most prominent were the differences in the incidence of gynecomastia (55% vs. 7%) and fluid retention (21% vs. 6%). The incidence of thromboembolic phenomena was comparable (8% vs. 5% in the Megestrol arm). Patients on the DES arm demonstrated a significantly greater median decrease in testosterone level. Correlation of the treatment arm assignment and the rate of tumor regression and the incidence of complete response revealed no significant difference between the arms. At 7 years, 16% of patients on the Megace arm and 21% of patients on the DES arm manifested evidence of local failure. CONCLUSIONS: The results of the study indicate comparable efficacy (using tumor clearance as an end point) of DES and Megestrol. Although DES appears more effective in suppressing testosterone, it is also associated with a higher incidence of drug-related toxicity.

Adenocarcinoma↗
PubMed1995

Androgen deprivation with radiation therapy compared with radiation therapy alone for locally advanced prostatic carcinoma: a randomized comparative trial of the Radiation Therapy Oncology Group.

OBJECTIVES: Androgen deprivation therapy before and during radiation therapy could, by reducing tumor volume, increase local tumor control, disease-free survival, and overall survival in patients with locally advanced adenocarcinomas of the prostate. METHODS: In a randomized controlled clinical trial, patients with large T2, T3, and T4 prostate tumors, but no evidence of osseous metastasis, were randomized to receive goserelin 3.6 mg subcutaneously every 4 weeks and flutamide 250 mg orally three times daily 2 months before and during the radiation therapy course (Arm I) compared with radiation therapy alone (Arm II). Pelvic irradiation was administered with 1.8 to 2.0 Gy per day to a total dose of 45 +/- 1 Gy followed by a boost to the prostate target volume to a total dose of 65 to 70 Gy. RESULTS: Of 471 randomized patients, 456 were evaluable, 226 on Arm I and 230 on Arm II. With a median potential follow-up of 4.5 years, the cumulative incidence of local progression at 5 years was 46% in Arm I and 71% in Arm II (P < 0.001). The 5-year incidence of distant metastasis on Arms I and II was 34% and 41%, respectively (P = 0.09). Progression-free survival rates including normal prostate-specific antigen (PSA) levels for 396 patients with at least one PSA recorded were 36% in Arm I and 15% in Arm II at 5 years (P < 0.001). At this time, no significant difference in overall survival could be detected (P = 0.7). CONCLUSIONS: Short-term androgen deprivation with radiation therapy results in a marked increase in local control and disease-free survival compared with pelvic irradiation alone in patients with locally advanced carcinoma of the prostate. Long-term surveillance is required to assess effects on overall survival.

Adenocarcinoma↗
PubMed1991

High altitude dives from 7000 to 14,200 feet in the Himalayas.

Indian Navy divers carried out no-decompression dives at altitudes of 7000 to 14,200 ft (2134-4328 m) in the Nilgiris and Himalayas from May to July 1988. Seventy-eight dives on air and 22 dives on oxygen were carried out at various altitudes. The final dives were at Lake Pangong Tso (4328 m) in Ladakh, Himalayas, to a maximum of 140 feet of sea water (fsw) [42.6 meters of sea water (msw)] equivalent ocean depth in minimum water temperature of 2 degrees C. Oxygen diving at 14,200 ft (4328 m) was not successful. Aspects considered were altitude adaptation, diminished air pressure diving, hypothermia, and remote area survival. Depths at altitude were converted to depths at sea level and were applied to the Royal Navy air tables. Altitude-related manifestations, hypoxia, hypothermia, suspected oxygen toxicity, and equipment failure were observed. It is concluded that stress is due to effects of altitude and cold on man and equipment, as well as changes in diving procedures when diving at high altitudes. Equivalent air depths when applied to Royal Navy tables could be considered a safe method for diving at altitudes.

Acclimatization↗
PubMed1990

Phase II Radiation Therapy Oncology Group study of hormonal cytoreduction with flutamide and Zoladex in locally advanced carcinoma of the prostate treated with definitive radiotherapy.

In patients with locally advanced (bulky) carcinoma of the prostate, definitive radiotherapy is associated with a high rate of local recurrence. The Radiation Therapy Oncology Group (RTOG) has conducted several studies evaluating hormonal cytoreduction (used as an induction regimen) as a means of improving the local control rate. RTOG 85-19 tested an induction regimen consisting of a depot LH-RH agonist (Zoladex) and an antiandrogen (flutamide). Eligible patients were those with bulky primary lesions (stage B2 and C) with disease confined to the pelvis. Zoladex was administered every 29 days via a subcutaneous injection. Flutamide was given by mouth in a dose of 250 mg t.i.d. Administration of the drugs was initiated 2 months prior to start of radiotherapy and was terminated at completion of the radiotherapy course. Radiotherapy consisted of 180-200 rad/day, 4,400-4,500 rad to the regional lymphatics, and 6,500-7,000 rad to the prostate. The primary aim of the study was to evaluate the effectiveness and toxicity of the combined (hormonal cytoreduction plus definitive radiotherapy) regimen. Thirty-one patients were accessioned; 30 are analyzable. The drug-related toxicity appears acceptable. It included appearance of diarrhea before initiation of radiotherapy in two patients, nausea during the 2nd week of drug administration in two patients, and skin rash in three patients. These phenomena appear to be related to flutamide. Hot flashes were recorded in 17 patients. With a minimum follow-up of 2 years, clearance of the primary lesions (by clinical examination) was documented in 28 of 30 patients. During the 1st year, two of 30 patients died (of unrelated causes) with residual palpable tumors. The observed toxicity appears acceptable and the response rate encouraging. A phase III study comparing the tested regimen against radiotherapy alone appears warranted.

Buserelin↗
PubMed1989

Radiotherapy alone and chemoradiation for nonmetastatic esophageal carcinoma. A critical review of chemoradiation.

Sixty-five patients with nonmetastatic (Stages I, II, and III) esophageal cancer (EC) were treated with radiotherapy (RT) alone (56.00 to 61.00 Gy in 6 to 7 weeks) or synchronous combinations of radiotherapy and chemotherapy (RT-CT). RT-CT consisted of 41.40 to 50.40 Gy in 4.5 to 8 weeks with continuous infusion 5-fluorouracil 5-FU (1000 mg/m2/d for 4 days in weeks 1, 4, and 8), mitomycin C (10 mg/m2 intravenously [IV] in weeks 1 and 8), cisplatin (75 mg/m2 IV in week 4). Maintenance CT consisted of methotrexate (200 mg/m2 IV), leucovorin (10 mg/m2 orally every 6 hours for 5 doses), and 5-FU (600 mg/m2 IV) in weeks 10, 12, and 14. Thirty-five patients treated by RT alone (Group A) were comparable in terms of age, sex, AJC staging, histologic condition, and location of primary with 30 patients treated by RT-CT (Group B). In Group A (range, 2- to 144+ months), two patients (42 and 144 months) are alive and well. In Group B (range, 2- to 59+ months), 12 patients (7 to 59 months) are alive and well. Median survival in Group A is 8 months, compared with 15 months for patients achieving a complete response (CR) in Group B. Patients in Group B achieved a 77% CR rate by endoscopy-biopsy, whereas 30% of the patients in Group A achieved a CR (P = 0.0001). The recurrence rates at the primary site/regional nodes were 77% and 27% in Groups A and B, respectively (P = 0.0001). The incidences of distant metastases were 29% and 20%, respectively (P = 0.423). In Group A, the 1-year and 2-year cumulative survival rates were 27% and 13%, respectively. In Group B, the cumulative survival rates were 53% at 1 year and 29% at 2 years (P = 0.023). Aside from reversible myelotoxicity, the incidences of pulmonary fibrosis, esophagitis, and fistulae formation were less frequent in the combined technique treatment group. A compilation of reported chemoradiation protocols for EC indicates consistently improved 1-year and 2-year survival rates, compared with surgical and RT series. The key to further improvement in the treatment of EC appears to lie in increasing the biologic response (RT fractionation and endocavitary RT) and optimal use of multiple effective CT agents with nonadditive toxicities.

Adenocarcinoma↗
PubMed1989

Hormonal cytoreduction in locally advanced carcinoma of the prostate treated with definitive radiotherapy: preliminary results of RTOG 83-07.

RTOG 83-07 is a Phase II randomized protocol designed to compare the efficacy and toxicity of Megestrol vs Diethylstilbestrol (DES) used as cytoreductive agents prior to and during radiotherapy. The end-points of this study include tumor clearance rate, effect on serum testosterone, local-regional control, disease-free interval, and survival. Eligible patients were those with histologically confirmed locally advanced adenocarcinoma, clinical Stage B2 and C without regional lymph node involvement, or with lymph node involvement limited to the pelvis. Patients with medical conditions potentially predisposing to cardiovascular (thromboembolic) sequelae of endocrine therapy were not eligible. Patients were stratified by clinical stage, histological grade, and nodal status and were randomized to receive either Megestrol 40 mg PO tid or Diethylstilbestrol 1 mg PO tid. The drugs were started 2 months prior to initiation of radiotherapy and were continued throughout the radiotherapy course. Radiotherapy consisted of 44 to 46 Gy, 1.8 to 2 Gy per day to the regional lymphatics followed by a boost to the prostate consisting of 20 to 25 Gy, 1.8 to 2 Gy per day to a total of 65 to 70 Gy. Serum testosterone levels were recorded throughout the treatment course. Tumor response was assessed clinically and radiographically (CT scan). From March 1983 through June 1986 a total of 203 patients were accessioned to the study; 197 were analyzable. Correlation of the incidence of drug related toxicity and treatment arm assignment revealed a significantly higher incidence of complications in the Diethylstilbestrol (DES) arm. The most prominent were the differences in the incidence of gynecomastia (55% vs 7%) and fluid retention (21% vs 6%). The incidence of thromboembolic phenomena was comparable (8% vs 5% in the Megestrol arm). Although patients on the DES arm demonstrated a significantly greater median decrease in testosterone level, correlation of the treatment assigned to the rate of tumor regression and the incidence of complete response revealed no significant difference between the arms. At 3 years only 6.5% of the evaluable patients manifested evidence of local failure. The results of the study indicate comparable efficacy (using tumor clearance as an end-point) of DES and Megestrol. While DES appears more effective in suppressing testosterone it is also associated with a higher incidence of toxicity. The cytoreduction (using either DES, Megestrol, or an alternative regimen) concept remains to be tested in a Phase III study comparing it to radiotherapy alone.

Adenocarcinoma↗
PubMed1988

Clinical potential of synchronous radiotherapy and chemotherapy for advanced squamous cell carcinoma.

The equivocal results of past treatment regimens in which concurrent radiotherapy and chemotherapy were used may have resulted from a lack of site-specific active drugs that were also true radiation sensitizers. This report demonstrates an experience with 3 chemotherapeutic agents, 5-fluorouracil, cisplatin, and mitomycin, given simultaneously with radiation for locally advanced squamous cell carcinomas of such diverse sites as the anal canal, cervix, and esophagus. Early results show that the toxicity of these combination regimens is generally acceptable and indicate that such synchronous combination treatments may be superior in local control and survival to radiotherapy alone.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Definitive combined modality therapy of carcinoma of the anus. A report of 30 cases including results of salvage therapy in patients with residual disease.

Thirty patients with epidermoid carcinoma of the anus, ranging in age from 40 to 89 years, were treated with combined chemotherapy (CT) and radiation therapy (RT) in lieu of abdominoperineal resection. Two courses of 5-FU (1000 mg/m2/day X four days) by continuous infusion and mitomycin-C (10-15 mg/m2 IV bolus on day 1 of each course) were given 3 to 4 weeks apart simultaneously, with whole pelvis RT to 4140 to 4500 cGy. Twenty-one of 28 patients had T3-T4 primaries and ten had positive nodes (N1). Two of the 30 patients were treated for local recurrence following surgical excision and one was treated immediately after local excision. Twenty-six of the 30 patients attained biopsy-confirmed complete remission. Four of the 30 patients demonstrated residual disease at completion of therapy but all subsequently achieved complete remission with additional nonsurgical treatment. One patient, initially treated for local recurrence following excision failed locally at four years and was salvaged with chemotherapy followed by abdominoperineal resection. No patient has experienced distant failure. Twenty-seven of 30 patients were alive and disease free after 9 to 76 months of follow-up and three died, disease-free, of unrelated causes. Acute toxicities were mild and did not necessitate interruption of treatment. A brisk perineal reaction and diarrhea were noted in all patients. Late complications were unusual. All patients were treated in a community-based, private practice setting. The authors conclude that combined CT-RT, as employed herein, represents a first-line curative treatment for the majority of patients with epidermoid anal carcinoma. For patients who demonstrate residual disease following this therapy, salvage regimens such as 5-FU infusion and cisplatin, or sequential MTX-5-FU-Leucovorin with additional synchronous RT should be employed before resorting to radical surgery.

Adult↗