Immunotherapy of metastatic colorectal cancer with vitamin D-binding protein-derived macrophage-activating factor, GcMAF.

Serum vitamin D binding protein (Gc protein) is the precursor for the principal macrophage-activating factor (MAF). The MAF precursor activity of serum Gc protein of colorectal cancer patients was lost or reduced because Gc protein is deglycosylated by serum alpha-N-acetylgalactosaminidase (Nagalase) secreted from cancerous cells. Deglycosylated Gc protein cannot be converted to MAF, leading to immunosuppression. Stepwise treatment of purified Gc protein with immobilized beta-galactosidase and sialidase generated the most potent macrophage-activating factor (GcMAF) ever discovered, but it produces no side effect in humans. Macrophages treated with GcMAF (100 microg/ml) develop an enormous variation of receptors and are highly tumoricidal to a variety of cancers indiscriminately. Administration of 100 nanogram (ng)/ human maximally activates systemic macrophages that can kill cancerous cells. Since the half-life of the activated macrophages is approximately 6 days, 100 ng GcMAF was administered weekly to eight nonanemic colorectal cancer patients who had previously received tumor-resection but still carried significant amounts of metastatic tumor cells. As GcMAF therapy progressed, the MAF precursor activities of all patients increased and conversely their serum Nagalase activities decreased. Since serum Nagalase is proportional to tumor burden, serum Nagalase activity was used as a prognostic index for time course analysis of GcMAF therapy. After 32-50 weekly administrations of 100 ng GcMAF, all colorectal cancer patients exhibited healthy control levels of the serum Nagalase activity, indicating eradication of metastatic tumor cells. During 7 years after the completion of GcMAF therapy, their serum Nagalase activity did not increase, indicating no recurrence of cancer, which was also supported by the annual CT scans of these patients.

Adjuvant immunochemotherapy with protein-bound polysaccharide K for colon cancer in relation to oncogenic beta-catenin activation.

PURPOSE: Protein-bound polysaccharide K is an immunotherapeutic agent that promotes apoptosis by inhibiting nuclear factor-kappaB activation in cancer cells. We previously showed that oncogenic beta-catenin activates nuclear factor-kappaB and inhibits apoptosis by up-regulating beta-transducin repeat-containing protein. We investigated whether the activation state of beta-catenin in the primary tumor is associated with differences in survival rates of patients with colon cancer undergoing immunochemotherapy with 5-fluorouracil plus polysaccharide K vs. chemotherapy with 5-fluorouracil alone. METHODS: We assessed the activation states of beta-catenin and nuclear factor-kappaB in the primary tumors of 202 colon cancer patients, and analyzed the data in terms of the clinicopathologic characteristics and survival of patients undergoing the two forms of adjuvant therapy. RESULTS: We found two distinct patterns of nuclear accumulation of activated beta-catenin in the tumor cells: diffuse nuclear accumulation in 89 cases (44 percent) and selective nuclear accumulation at the tumor invasion front in 18 cases (9 percent). Nuclear factor-kappaB activation was found in 64 cases (32 percent). In patients with diffuse nuclear accumulation-type beta-catenin activation, immunochemotherapy significantly improved recurrence-free survival, cancer death survival, and overall survival rates compared with patients receiving chemotherapy alone. No survival benefit was found in cases with nuclear accumulation at the tumor invasion front-type beta-catenin activation or no activation. Similarly, immunochemotherapy favored the survival of patients with nuclear factor-kappaB activation. Multivariate analysis established the TNM stage and administration of polysaccharide K as independent prognostic factors in the patients with diffuse nuclear accumulation-type beta-catenin activation. CONCLUSIONS: The presence of diffuse nuclear accumulation-type beta-catenin activation identifies patients with colon cancer who respond better to immunotherapy with polysaccharide K.

Efficacy of adjuvant immunochemotherapy with polysaccharide K for patients with curatively resected colorectal cancer: a meta-analysis of centrally randomized controlled clinical trials.

The benefits of immunochemotherapy employing the biological response modifier polysaccharide K (PSK) for patients with curatively resected colorectal cancer was reassessed by means of a meta-analysis of data with center randomization from 1,094 patients enrolled in three clinical trials. In all three trials, patients were followed up for at least 5 years after surgery and enrollment of the last patient and outcomes for standard chemotherapy were compared with those for chemotherapy plus PSK. The endpoints were overall survival and disease-free survival; and intent-to-treat analysis was performed without patient exclusion. Data were analyzed using the weighted average of the individual log hazard ratios. The overall survival risk ratio for all eligible patients was 0.71 (95% confidence interval (CI) : 0.55-0.90; P=0.006), and the disease-free survival risk ratio was 0.72 (95% CI: 0.58-0.90; P=0.003). The results of this meta-analysis suggest that adjuvant immunochemotherapy with PSK can improve both survival and disease-free survival of patients with curatively resected colorectal cancer.

Phase I study of paclitaxel and cisplatin for patients with advanced or recurrent gastric cancer.

BACKGROUND/AIMS: The present phase I study was planned to define the toxicities, maximum tolerated dose (MTD), and pharmacokinetics of the combination of paclitaxel and cisplatin in patients with advanced or recurrent gastric cancer, and to recommend a dose for the phase II study. METHODOLOGY: Patients were required to have performance status of 0 to 1, to be between 15 and 74 years of age, and to have adequate organ function. The cisplatin was administered at a fixed dose of 25mg/m2 and paclitaxel was administered at four dose levels (60, 70, 80, and 90mg/m2). Plasma sampling was performed to characterize the pharmacokinetics and pharacodynamics of paclitaxel. RESULTS: All of the 15 patients entered were assessable for toxicity and response and were subject to analysis of dose-limiting toxicity (DLT) and MTD. Neutropenia (grade 4, for 3 days or more; n=2) indicated DLT at dose level 4 (90mg/m2). The MTD for this regimen was 90mg/m2/week of paclitaxel for 3 weeks. Tumor response occurred in 7 of the 15 patients and the overall response rate was 57.1%. The pharmacokinetic profiles of paclitaxel were similar to those observed after the administration of each dose as a single agent. CONCLUSIONS: Our study demonstrated that the level 3 dosage (80mg/m2 of paclitaxel and 25mg/m2 of cisplatin) is recommended for this combination chemotherapy. This phase I study showed favorable antitumor activity and fewer adverse reactions relative to other types of chemotherapy.

An individual patient data meta-analysis of adjuvant therapy with carmofur in patients with curatively resected colon cancer.

BACKGROUND: Oral carmofur, either as a single or in combination with other chemotherapeutic agents, has been used as adjuvant chemotherapy for curatively resected colon cancer patients. Past trials and meta-analyses indicate that it is somewhat effective in extending survival of patients with this cancer. The objective of this study was to perform a reappraisal of randomized clinical trials conducted in this regard. METHODS: We designed an individual patient-based meta-analysis of relevant clinical trials to examine the benefit of oral carmofur for curatively resected colon cancer in terms of overall survival (OS) and disease-free survival (DFS). RESULTS: We analyzed individual patient data of three randomized clinical trials, which met the predetermined inclusion criteria. These three trials had a combined total of 2152 patients, carmofur as adjuvant chemotherapy compared with surgery-alone, 5 years follow-up, intention-to-treat-based analytic strategy and similar end points (OS and DFS). In a pooled analysis, 5 year OS rates were 80.4 and 76.4%, and 5 year DFS rates 76.9 and 71.0%, respectively, in carmofur and surgery-alone group. Oral carmofur had significant advantage over surgery-alone in terms of both OS [pooled hazard ratio, 0.82; 95% confidence interval (CI) = 0.68-0.99; P = 0.043] and DFS (pooled hazard ratio, 0.77; 95% CI = 0.65-0.91; P = 0.003). CONCLUSIONS: This individual patient-based meta-analysis demonstrated that oral carmofur significantly improves both OS and DFS in patients with curatively resected colon cancers.

Phase I evaluation of continuous 5-fluorouracil infusion followed by weekly paclitaxel in patients with advanced or recurrent gastric cancer.

OBJECTIVE: We conducted a phase I trial of escalating doses of weekly paclitaxel (Taxol) in combination with a fixed systemic administration of 5-fluorouracil (5-FU) in patients with advanced or metastatic gastric cancer. METHODS: Patients with advanced or recurrent gastric cancer were treated with escalating doses of weekly paclitaxel as a 60 min intravenous (i.v.) infusion, along with a fixed dose of continuous 5-FU infused over 5 days. Plasma sampling was performed to characterize the pharmacokinetics and pharmacodynamics of paclitaxel. RESULTS: Eighteen patients received combination therapy at four dose levels of weekly Taxol, ranging from 60 to 90 mg/m2/week. Dose-limiting toxicities > grade 3 were observed at the 90 mg/m2/week dose level. Toxicities included anemia, neutropenia, thrombocytopenia, nausea and alopecia. Two episodes of grade 4 neutropenia occurred in two of the three patients receiving this dose. At each dose level, pharmacological studies documented the persistence of significant serum paclitaxel levels over 24 h after drug administration. The maximum tolerated dose (MTD) for this regimen was 90 mg/m2/week of paclitaxel for 3 weeks plus 600 mg/m2/day of continuous 5-FU for 5 days. CONCLUSIONS: The combination of weekly paclitaxel and 5-FU demonstrated an acceptable toxicity profile and feasible pharmacokinetic results suggesting its practical applicability. Based on these findings, the recommended dose and schedule for phase II study of combination chemotherapy is paclitaxel 80 mg/m2/week x 3 over 4 weeks, and continuous 5-FU 600 mg/m2/day x 5 days every 4 weeks.

Preoperative CEA and PPD values as prognostic factors for immunochemotherapy using PSK and 5-FU.

PURPOSE: Immunochemotherapy using PSK used as postoperative adjuvant chemotherapy for colorectal cancer in Japan, is a treatment that depends on the immunocompetence of the host. Therefore, we analyzed the data of Hokuriku district conducted by the CIP study group to compare the long-term survival for preoperative CEA level and PPD reaction. PATIENTS AND METHODS: Between February 1991 and March 1993, 87 patients with primary colon cancer and macroscopic lymph node metastasis (macroscopic Dukes' C) underwent macroscopic curative resection. The patients were randomly allocated to receive 5-FU/PSK therapy or 5-FU alone. The 7-year disease-free survival (DFS), 7-year overall survival (OS) and 7-year cancer death survival (CDS) were compared using the preoperative CEA levels and PPD values. RESULTS: In cases with preoperative CEA level > or =3.0 ng/mL, the 7-year DFS, 7-year OS and 7-year CDS were significantly better in the PSK group (85.7, 90.5, 90.5%) than in the control group (52.4, 52.4, 57 1%; p=0.019, 0.007, 0.014,). In cases with preoperative PPD level <19.0 mm, the 7-year DFS, 7-year OS and 7-year CDS were significantly better in the PSK group (85.7, 85.7, 89.3%) than in the control group (56.7, 60.0, 63.3%; p=0.018, 0.036, 0.028). Recurrence was significantly less in the PSK group. The DFS tended to be superior in the PSK group (87.4%) compared to the control group (69.9%) for hematogenous metastasis. CONCLUSION: The present study demonstrated that preoperative CEA and PPD, that can be measured easily in the clinical setting, may be effective indicators of postoperative adjuvant immunochemotherapy using PSK.

Sialyl Lewisa expression as a predictor of the prognosis of colon carcinoma patients in a prospective randomized clinical trial.

BACKGROUND: The metastatic potential of tumors is dependent on the cell to cell adhesion by cell surface carbohydrate antigens. Thus, expression of sialyl Lewis(a), which is one of the important molecules of cell surface carbohydrates, may serve as a prognostic marker of aggressive and metastasizing tumor growth. However, the prognostic value of sialyl Lewis(a) expression in colon cancer is still controversial. METHODS: In this study, we investigated the expression of sialyl Lewis(a) antigen in 233 colon cancer specimens from patients who were registered in a prospective adjuvant immunochemotherapy clinical trial. The clinical course and the prognosis of the patients were evaluated after all the immunohistochemical analyses had been performed. RESULTS: Sialyl Lewis(a) expression levels were correlated with both overall survival (P = 0.0006) and disease-free survival (P = 0.004) in all patients with the log-rank test. This result could be assumed to have been influenced by the difference in the metastatic preponderance in a high versus low sialyl Lewis(a) expression in the tumor cells. CONCLUSION: This prospective study in a randomized controlled trial suggests that sialyl Lewis(a) expression levels may serve as an indicator of the metastatic potential of colon cancer cells, which would strongly predict the prognosis.

Statistical comparison of random allocation methods in cancer clinical trials.

The selection of a trial design is an important issue in the planning of clinical trials. One of the most important considerations in trial design is the method of treatment allocation and appropriate analysis plan corresponding to the design. In this article, we conducted computer simulations using the actual data from 2158 rectal cancer patients enrolled in the surgery-alone group from seven randomized controlled trials in Japan to compare the performance of allocation methods, simple randomization, stratified randomization and minimization in relatively small-scale trials (total number of two groups are 50, 100, 150 or 200 patients). The degree of imbalance in prognostic factors between groups was evaluated by changing the allocation probability of minimization from 1.00 to 0.70 by 0.05. The simulation demonstrated that minimization provides the best performance to ensure balance in the number of patients between groups and prognostic factors. Moreover, to achieve the 1 percentile for the p-value of chi-square test around 0.50 with respect to balance in prognostic factors, the allocation probability of minimization was required to be set to 0.95 for 50, 0.80 for 100, 0.75 for 150 and 0.70 for 200 patients. When the sample size was larger, sufficient balance could be achieved even if reducing allocation probability. The simulation using actual data demonstrated that unadjusted tests for the allocation factors resulted in conservative type I errors when dynamic allocation, such as minimization, was used. In contrast, adjusted tests for allocation factors as covariates improved type I errors closer to the nominal significance level and they provided slightly higher power. In conclusion, both the statistical and clinical validity of minimization was demonstrated in our study.

Long-term effect of 5-fluorouracil enhanced by intermittent administration of polysaccharide K after curative resection of colon cancer. A randomized controlled trial for 7-year follow-up.

BACKGROUND AND AIMS: The efficacy of a biological response modifier polysaccharide K in adjuvant immunochemotherapy was evaluated in primary colon cancer patients with macroscopic Dukes' C after curative resection. PATIENTS AND METHODS: Employing the minimization method using three factors (lymph node metastases, preoperative serum CEA level, and institution), 446 patients were allocated into groups P and C. Group P received immunochemotherapy, oral PSK (3 g per day) followed by oral 5-FU (200 mg/body per day), while group C received only intermittent chemotherapy, oral 5-FU (200 mg per day) followed by 4-week rest. Both groups received ten courses. RESULTS: Survival for cancer death was significantly higher in group P than in group C, but there was no difference in 7-year disease-free survival or overall survival had. CONCLUSION: Repeated alternating administration with PSK followed by 5-FU can improve survival for cancer death.

The usefulness of CEA and/or CA19-9 in monitoring for recurrence in gastric cancer patients: a prospective clinical study.

BACKGROUND: Many studies on postoperative carcinoembryonic antigen (CEA) and/or carbohydrate antigen (CA)19-9 monitoring after operation for gastric cancer have been reported, but most have been retrospective. METHODS: A nationwide observational study was implemented in 135 leading institutions in Japan to evaluate the significance of CEA and/or CA19-9 in postoperative monitoring for recurrence in patients with advanced gastric cancer. Three hundred and twenty-one patients examined in this analysis underwent radical gastrectomy at one of Japan's leading institutions between November 1993 and March 1996 and had been followed up for at least 5 years. Serum levels of CEA and CA19-9 were examined preoperatively and every 3 months postoperatively, with diagnostic imagings, such as chest X-ray, computed tomography (CT), and ultrasonography also being performed every 3 months. RESULTS: Recurrence was observed in 120 patients (peritoneum, 48; liver 16; lymph node, 16; multiple sites, 25; and others, 12). Sensitivities of CEA and either CEA or CA19-9, or both, for recurrence were 65.8% and 85.0%, respectively, both of which values were significantly higher than the preoperative positivities (28.3% and 45.0%, respectively). In most patients with high preoperative levels CEA and/or CA19-9, these tumor markers increased again at recurrence. Recurrent diseases were detected between 5 months after detection by diagnostic imagings and 12 months before detection by diagnostic imagings (mean of 3.1 +/- 3.6 months before detection by diagnostic imagings) and between 10 months after detection by diagnostic imagings and 13 months before detection by diagnostic imagings (mean of 2.2 +/- 3.9 months before detection by diagnostic imagings) by CEA and CA19-9 monitorings, respectively. CONCLUSION: These results suggest that CEA and/or CA19-9 monitoring after operation was useful to predict the recurrence of gastric cancer, especially in almost all the patients with high preoperative levels of these markers.

Thymidylate synthase expression as a predictor of the prognosis of curatively resected colon carcinoma in patients registered in an adjuvant immunochemotherapy clinical trial.

The expression levels of thymidylate synthase (TS) affect the sensitivity of tumor cells to fluorinated pyrimidine cytotoxic agents and determine the response of patients with colorectal cancer to fluorinated-pyrimidine-based chemotherapy. The correlation between the expression of TS and the prognosis of patients with colorectal cancer was examined in a prospective study. Evaluation of biomarkers including TS expression was performed using tumor specimens from 229 colorectal cancer patients. Immunohistochemical analysis of TS expression was performed using an antibody raised against a C-terminal epitope (D186-V313) of the human TS. The intensity of TS staining and the expression of other biomarkers were blindly scored. The five-year survival rates were 63.4% and 85.6% among patients with high and low intratumoral TS expressions, respectively (p=0.0007). Similarly, the disease-free survival (DFS) rate was 51.2% and 80.3% in the high and low TS expression groups, respectively (p=0.0004). In a subset analysis of Dukes' stage C patients, the survival and DFS rates were 44.0% and 40.0% in the high TS expression group, and 73.5% and 67.4% in the low TS expression group, respectively. Significant differences were observed in both survival (p=0.0048) and DFS (p=0.0054) rates. No significant correlation was observed between the expression of other biomarkers and prognosis. Significantly poorer prognosis of curatively resected colon cancer in patients with high TS expression levels in tumor tissue was confirmed by a double-blind prospective study conducted on samples obtained from patients enrolled in an adjuvant immunochemotherapy randomized clinical trial.

A randomized controlled trial of postoperative adjuvant immunochemotherapy for colorectal cancer with oral medicines.

Postoperative adjuvant chemotherapy reportedly improves advanced colorectal cancer patients' survival, however, it is necessary to assess what regimens are useful. Doxifluridine (5'-DFUR) is an intermediate of capecitabine approved in Europe and USA to treat metastatic colorectal cancer. 5'-DFUR is metabolized to 5-fluorouracil (5-FU) by thymidine phosphorylase existing in tumor at high concentrations, suggesting high 5-FU levels in tumor tissues and lesser complications. Present study compared usefulness of 5'-DFUR to that of oral 5-FU. Patients were enrolled at 38 centers from April 1993 to September 1996. They had diagnosed colorectal cancer of TNM stages II and III, and underwent macroscopic curative resection. Patients were prestratified into colon or rectum cancer and allocated into either 5'-DFUR (5'-DFUR 460 mg/m(2)/day + PSK 3 g/day) or 5-FU (5-FU 115 mg/m(2)/day + PSK 3 g/day) group by dynamic randomization (stratification factors such as depth of tumor, degree of lymph node metastasis, and location of tumor). Drugs were orally administered daily from postoperative week 2 to 54, with 6 mg/m(2) mitomycin C at operation and following days. Subjects for analysis were 277 in 5'-DFUR and 281 in 5-FU groups. Median follow-up was 6.5 years. Although no differences in overall survival curves were detected, multivariate analysis showed that 5'-DFUR + PSK regimen was a significantly better prognostic factor in patients with Dukes B or C (risk ratio, 1.451; p=0.048); with tumor depth of pT3 or pT4 (risk ratio, 1.568; p=0.020). For patients with advanced colorectal cancer, 5'-DFUR + PSK therapy may possibly be more useful than 5-FU + PSK, but further study is required.

Meta-analysis of five studies on tegafur plus uracil (UFT) as post-operative adjuvant chemotherapy for breast cancer.

Meta-analysis of 5 studies on postoperative breast cancer cases (2 studies on surgery alone vs. tegafur plus uracil (UFT) and 3 studies on tamoxifen (TAM) alone vs. TAM + UFT) were carried out to evaluate the anticancer drug UFT in oral postoperative adjuvant chemotherapy. Of the 1973 patients enrolled, 1898 were eligible and 75 were excluded (exclusion rate 3.8%). There was no bias in major background factors in either the UFT-treated (965) or non-UFT-treated (933) groups. The reduction in the odds of death and the odds of recurrence were 17 +/- 17% (p = 0.33) and 21 +/- 11% (p = 0.060), respectively. Multivariate analysis using Cox's proportional hazards model emphasized the effectiveness of UFT treatment for suppression of recurrence compared with non-treatment with UFT (p = 0.038). Suppression of recurrence was remarkable in the group treated with UFT for 2 years. (the reduction in the odds of recurrence: 23 +/- 11%, p = 0.048) Stratified analysis was applied concerning recurrence, and improved results were obtained in premenopausal cases (the reduction in the odds of recurrence: 33 +/- 11%, p = 0.019). These results suggested that UFT treatment for 2 years was effective as postoperative adjuvant chemotherapy for stage I - IIIA breast cancer for the prolongation of the recurrence-free survival period.

Retrospective study on thymidylate synthase as a predictor of outcome and sensitivity to adjuvant chemotherapy in patients with curatively resected colorectal cancer.

We carried out a retrospective evaluation of thymidylate synthase (TS) expression in tumor tissue, and its relation to outcome and response to treatment. The treatment consisted of chemotherapy with tegafur and uracil (UFT). The study group comprised 245 patients with curatively resected Dukes' stage B or C colorectal cancer who were postoperatively enrolled in a controlled study and assigned to receive UFT or no adjuvant chemotherapy. TS expression in tumor tissue was evaluated immunohistochemically with the use of recombinant human TS-specific antibody. Results were as follows. There was no relation between TS expression and the rate of 5-year disease-free survival. Similar results were obtained in both colonic and rectal tumors. The rate of 5-year disease-free survival was significantly higher in the UFT group than in the group receiving no adjuvant chemotherapy ( =0.0055). The difference in survival became more marked among patients whose tumors had diffuse TS expression ( =0.0027). There was no difference in survival between the treatment groups among patients whose tumors had focal TS expression. We conclude that, although unrelated to outcome, TS activity may be useful in predicting the response to adjuvant chemotherapy with UFT in patients with curatively resected Dukes' stage B or C colorectal cancer.

Efficacy of adjuvant immunochemotherapy with OK-432 for patients with curatively resected gastric cancer: a meta-analysis of centrally randomized controlled clinical trials.

The benefit of immunochemotherapy employing a streptococcal preparation, OK-432 (Picibanil), in patients with curatively resected gastric cancer was reassessed by meta-analysis of data from 1,522 patients enrolled in six clinical trials with central randomization. All six trials began between 1985 and 1993, and patients were followed-up for at least 3 years after surgery and enrollment of the last patient. In these trials, standard chemotherapy was compared with the same chemotherapy plus OK-432. The endpoint was overall survival and intent-to-treat analysis was done without patient exclusion. Data were analyzed using the Mantel-Haenszel method. The 3-year survival rate for all eligible patients in the six trials was 67.5% in the immunochemotherapy group versus 62.6% in the chemotherapy group. The 3-year overall survival odds ratio was 0.81 (95% confidence interval: 0.65-0.99). The treatment effect was shown to be statistically significant (p = 0.044). The results of this meta-analysis suggest that immunochemotherapy after surgery with OK-432 can improve the survival of patients with curatively resected gastric cancer.

The effect of adjuvant 5'-deoxy-5-fluorouridine in early stage breast cancer patients: results from a multicenter randomized controlled trial.

To assess the efficacy of 5'-DFUR, an intermediate of capecitabine, for adjuvant treatment of early breast cancer, we conducted an open-labeled multi-center randomized controlled trial to compare postoperative 5'-DFUR treatment with surgery alone. We enrolled 1217 primary breast cancer patients and randomly assigned them into two treatment groups; one received six-month postoperative 5'-DFUR treatment by consecutive or intermittent administration, and the other surgery alone. Follow-up surveys were conducted once a year for all subjects simultaneously and examined their outcome/presence or absence of the cancer recurrence. The central study committee reviewed all follow-up data and judged the recurrence data to be used for the analysis. Eight-year follow-up data showed no significant differences in relapse-free and overall survival between the two groups, and 5'-DFUR treatment regimen showed an extremely high tolerance. Possible explanations are discussed for the finding of no significant survival difference between adjuvant 6-month 5'-DFUR monotherapy and surgery alone in early breast cancer.

Meta-analysis of Adjuvant Immunochemotherapy Using OK-432 in Patients With Resected Non-Small-Cell Lung Cancer.

SUMMARY: The benefits of immunochemotherapy with a penicillin-treated, lyophilized preparation of Streptococcus pyogenes, OK-432 (Picibanil), were reassessed in patients with resected non-small-cell lung cancer through a meta-analysis based on data from 1,520 patients enrolled in 11 randomized clinical trials. All 11 trials were started before 1991, and the subjects had been followed up for at least 5 years after surgery and randomization. In these trials, standard chemotherapy was compared with the same therapy plus OK-432. The endpoint of interest was overall survival, and analysis was based on intent-to-treat population without patient exclusion. Data were analyzed using the Mantel-Haenszel method. The 5-year survival rate for all eligible patients in the 11 trials was 51.2% in the immunochemotherapy group versus 43.7% in the chemotherapy group. The odds ratio (OR) for overall survival was 0.70 (95% CI = 0.56-0.87, p = 0.0010). Analysis of four trials in which central randomization was performed also reconfirmed a significantly longer survival time for the immunochemotherapy group (OR = 0.66, 95% CI = 0.44-1.00, p = 0.049). Based on these results of meta-analysis, it is postulated that postoperative adjuvant immunochemotherapy using OK-432 might improve the survival of patients after resection of non-small-cell lung cancer.