Hydronephrosis as a complication of adenocarcinoma of the lung

We describe a patient with adenocarcinoma of the lung who developed hydronephrosis secondary to compression by right common iliac lymph node metastases. The most common primary sites of cancers causing ureteral obstruction are the cervix, prostate, bladder and colo-rectum. To date, few reports of ureteral obstruction attributable to lung cancer have been published. Although rare, physicians should be aware that hydronephrosis can complicate the course of patients with non-small cell lung cancer.

Prognostic significance of mutant p53 protein, P-glycoprotein and glutathione S-transferase-pi in patients with unresectable non-small cell lung cancer

BACKGROUND

The prognostic significance of mutant p53 protein, p-glycoprotein (P-gp) and glutathione S-transferase-pi (GST-pi) in patients with unresectable non-small cell lung cancer (NSCLC) has not been established.

MATERIALS AND METHODS

We performed immunohistochemical staining of p53, P-gp and GST-pi using transbronchial biopsy specimens obtained from previously untreated NSCLC patients.

RESULTS

Of 45 patients examined, p53 immunostaining was positive in 18 (40%) patients. The objective response rate by cisplatin (CDDP)-based chemotherapy was significantly lower in patients with p53-positive tumors compared to those with p53-negative tumors (22% versus 59%, p = 0.0143). Survival of the patients with p53-positive tumors was significantly shorter than those with p53-negative tumors (median survival time: 4.6 months versus 12.2 months, p = 0.011), which was confirmed by the multivariate analysis (p = 0.0243). However, P-gp and GST-pi showed no significant relationship with either response rate or survival in patients with unresectable NSCLC receiving CDDP-based chemotherapy.

CONCLUSION

p53 alteration is an independent and significant indicator to predict unfavorable prognosis in patients with unresectable NSCLC.

Dramatic effect of ZD1839 ('Iressa') in a patient with advanced non-small-cell lung cancer and poor performance status

We describe the case of a 52-year-old Japanese woman with advanced adenocarcinoma of the lung, in whom once-daily treatment with 250 mg ZD1839 ('Iressa') demonstrated a marked antitumour effect. She had initially achieved a partial response with cisplatin-based combination chemotherapy, but had subsequently progressed and had failed to respond to salvage chemotherapy. She had also received whole-brain irradiation for brain metastases. On admission, the patient was confined to bed due to dyspnoea and had rapidly progressing hypoxia secondary to lymphangitis carcinomatosa and a massive right pleural effusion. She was treated with oxygen supplementation and oral ZD1839, which, within a week, led to marked tumour regression and gradually improving dyspnoea. The main adverse event observed was a grade 2 rash. A month after starting ZD1839 treatment, the patient was discharged without the need for oxygen supplementation and had since returned to full-time work. This is a demonstration of ZD1839 producing a dramatic clinical response when administered to a patient with poor performance status who had received extensive prior treatment with cytotoxic agents.'Iressa' is a trademark of the AstraZeneca group of companies.

Fractionated administration of irinotecan and cisplatin for treatment of extensive-disease small-cell lung cancer: a phase II study

BACKGROUND

A combination of irinotecan (CPT-11) and cisplatin (CDDP) was shown to be effective for extensive-disease small-cell lung cancer (ED-SCLC). To take maximum advantage of the synergistic effect between CPT-11 and CDDP, we designed a fractionated administration schedule.

PATIENTS AND METHODS

Between August 1995 and September 1998, 15 previously untreated patients with ED-SCLC were enrolled. Both CPT-11 at a dose of 50 mg/m2 and CDDP at a dose of 60 mg/m2 were given on days 1 and 8, and repeated every 4 weeks up to four cycles.

RESULTS

Fifteen patients were assessed for response and survival, and fourteen for toxicity. Although twelve patients (80.0%; 95% confidence interval, 51.9-95.7) achieved an objective response, complete response (CR) was not obtained. The median survival time and the actual 1-year survival rate were 9.4 months and 40.0%, respectively. Grade 3 or 4 leukopenia, neutropenia and diarrhea occurred in 71.4%, 100% and 14.3% of the patients, respectively. Enrollment into this study was stopped because CR, which was the primary endpoint, was not obtained in the consecutive 15 patients and the survival appeared to be inferior to the previous multi-institutional study (Kudoh et al, Clin Oncol 16: 1068-1074, 1998). The projected dose intensity in the present study was lower in CPT-11 and higher in CDDP compared to that in the previous report.

CONCLUSION

These results suggest that the dose intensity of CPT-11 may have a major role on the activity of SCLC in this combination.

Axillary metastasis as the first manifestation of occult breast cancer in a man: a case report

Breast cancer is extremely rare in men, accounting for less than 1% of all breast cancers. We describe a male patient with occult breast cancer that was confirmed immunohistochemically. To our best knowledge, this is the first case presenting axillary and supraclavicular metastases as the first manifestation of occult cancer of the male breast.

Parathyroid hormone-related protein measured at the time of first visit is an indicator of bone metastases and survival in lung carcinoma patients with hypercalcemia

BACKGROUND

Parathyroid hormone-related protein (PTH-rP) is a major cause of tumor-induced hypercalcemia (TIH) and frequently is found to be elevated in serum of patients with TIH. In the current study, the authors examined the usefulness of PTH-rP measurement at the time of first presentation in the follow-up of lung carcinoma patients with TIH.

METHODS

The authors retrospectively studied 23 of 1149 lung carcinoma patients who were found to have TIH at the time of first presentation for the correlation between serum PTH-rP and the development of bone metastases and survival compared with lung carcinoma patients without TIH who were matched by gender, age, Eastern Cooperative Oncology Group performance status, histological type of tumor, and stage of the disease.

RESULTS

Twenty-three lung carcinoma patients with TIH demonstrated significantly increased serum levels of PTH-rP (mean +/- standard error [SE], 84.1 +/- 16.5 pmol/L) compared with control patients without TIH (mean +/- SE, 36.2 +/- 2.0 pmol/L) at the time of first presentation, (P < 0.001). In these hypercalcemic patients, patients whose serum PTH-rP was > 150 pmol/L (n = 16) were found to have a significantly increased rate of bone metastases (71.4% vs. 12.5%; P = 0.01) and decreased survival (median survival of 1.4 months vs. 5.4 months; P < 0.015) compared with patients whose serum PTH-rP was < 150 pmol/L (n = 7).

CONCLUSIONS

The data from the current study suggest that serum PTH-rP as determined at the time of first presentation is a useful indicator of not only hypercalcemia but also bone metastasis and eventual survival in patients with lung carcinoma.

Daily low-dose cisplatin and concurrent thoracic irradiation for poor-risk patients with unresectable non-small-cell lung cancer

A pilot study was conducted to assess the efficacy and feasibility of daily low-dose cisplatin with concurrent thoracic irradiation for clinically unresectable non-small-cell lung cancer (NSCLC). Patients with inoperable NSCLC who had poor risk factors such as advanced age, poor performance status, poor lung function, or concomitant active malignancy were entered into the study. Low-dose cisplatin (6 mg/m2) was administered daily before concurrent thoracic irradiation (2 Gy/day; total dose of 60 Gy) was given. Twenty-five patients were registered. The majority of the patients had either stage IIIA (24.0%) or stage IIIB (60.0%) disease. Fifteen patients (60.0%) completed the planned treatment. Both chemotherapy and radiotherapy were stopped in 3 patients (12.0%) due to poor response, and 7 patients (28.0%) partly received radiotherapy alone as a result of their toxicity response. The proportion of total administered dose to planned dose was 90.9% for chemotherapy and 99.3% for radiotherapy, which were comparable to those in previous studies for LA-NSCLC patients without poor risk factors. Grade 3 leukopenia and neutropenia developed in 14 patients (56.0%) and 10 patients (40.0%), respectively, but grade 4 toxicity was not encountered. Grade 3 pneumonitis and esophagitis were observed in 4 patients (16.0%) and 2 patients (8.0%), respectively. The overall response rate was 60.0%. The median survival time was 22 months, and the 2-year survival rate was 50.3%. Daily low-dose cisplatin and concurrent thoracic irradiation were well tolerated even by poor-risk patients with NSCLC, and showed a therapeutic efficacy similar to that for good-risk patients.

Tandem high-dose chemotherapy supported by autologous peripheral blood stem cell transplantation for recurrent soft tissue sarcoma

BACKGROUND

Patients with recurrent soft tissue sarcoma (STS) are seldom curable, with 5-year survival rates of less than 10% in all large series. The role of high-dose chemotherapy (HDC) with hematopoietic stem cell support in this disease has not been established.

CASE REPORT

We report on two patients with recurrent STS who were treated with tandem HDC supported by autologous peripheral blood stem cell transplantation (PBSCT). One patient with malignant fibrous histiocytoma recurred with multiple lung metastases. This patient achieved a partial response after two cycles of induction chemotherapy consisting of ifosfamide and epirubicin. During four cycles of induction chemotherapy, peripheral blood stem cells (PBSCs) were harvested. Tandem high-dose ICE regimen (ifosfamide 3 g/m2 on days-7 to -3, carboplatin 400 mg/m2 on days-7, -5 and 3, etoposide 500 mg/m2 on days-7, -5 and 3) supported by autologous PBSCT gave rise to further regression of the tumors. Another patient with malignant hemangiopericytoma was treated by tandem high-dose ICE regimen supported by autologous PBSCT after the 3rd removal of abdominal tumors. Relapse-free intervals until the 1st, 2nd and 3rd relapses were 40, 19 and 22 months, respectively. Tandem high-dose ICE regimen might delay the relapse.

CONCLUSION

These observations suggest that a tandem high-dose ICE regimen with autologous PBSCT is feasible with some clinical efficacy in the control of refractory STS.

Risk of neutropenic fever and early infectious complications after autologous peripheral blood stem cell transplantation for malignant diseases

Autologous peripheral blood stem cell transplantation (auto-PBSCT) has facilitated high-dose chemotherapy for the treatment of various types of malignancy, but the factors affecting the treatment outcome have not been well defined. We evaluated patients who underwent auto-PBSCT (46 patients with hematological malignancies and 39 with solid tumors) to elucidate the risks of background factors, including age, in association with infectious complications. In contrast to former reports, faster engraftment did not influence the incidence of documented infection or neutropenic fever, whereas high age (age > or = 50 years old) and delayed platelet recovery (> or = 18 days) were demonstrated to be positively involved. The odds ratio (OR) for documented infection in elderly patients was 4.94 (95% confidence interval, 1.22-15.8). Another risk factor of infection was the HD-ICE regimen (ifosfamide, carboplatin, etoposide) given to patients with solid tumors (OR, 8.00; 95% confidence interval, 1.61-39.7). In conclusion, we found that elderly patients and patients on the HD-ICE regimen have a higher risk of infectious complications even after auto-PBSCT. Although the clinical indications for auto-PBSCT can be extended to elderly patients, thorough precautions should be taken against infectious complications during the pre-engraftment phase.

Comparison of chemosensitivity tests: clonogenic assay versus MTT assay

When the development of chemotherapeutic agents reaches the clinical trial stage, it is necessary to perform drug sensitivity tests quickly in order to select the most promising agents for the treatment of cancer. In order to assess the possibility of using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay as a substitute for the human tumor clonogenic assay (HTCA), we evaluated the correlation between the results obtained by these 2 assays in 5 human lung cancer cell lines. The correlation coefficient between the results of the HTCA and the MTT assay was 0.673, indicating a relatively good correlation. The correlation was most prominent in platinum analogues (r = 0.939) and good in anthracyclines/anthracenedione (r = 0.611). However, no significant correlation was observed in vinca alkaloids, etoposide, irinotecan, SN-38 (an active metabolite of irinotecan), and rhizoxin. The results of the MTT assay showed a high degree of correlation with those of the HTCA in predicting the sensitivity of cancer cell lines to platinum analogues, and anthracyclines/anthracenedione. These results suggest that the MTT assay may be more convenient and quickly performed than the HTCA and can replace HTCA in evaluating the effects of anticancer agents, especially the platinum analogues and anthracyclines/anthracenedione.

A phase III randomized trial comparing vindesine and cisplatin with or without ifosfamide in patients with advanced non-small-cell lung cancer: long-term follow-up results and analysis of prognostic factors

In order to evaluate the activity and toxicity of a three-drug combination of vindesine, ifosfamide and cisplatin (VIP) for inoperable non-small-cell lung cancer (NSCLC), we conducted a randomized trial comparing VIP with a two-drug combination of cisplatin and vindesine (VP). Between September 1987 and March 1992, a total of 132 patients with stage III or IV NSCLC were randomly allocated to either VIP or VP. The VIP regimen consisted of vindesine (VDS 3 mg/m(2) on days 1 and 8), ifosfamide (IFX 1300 mg/m(2) on days 1-5), and cisplatin (CDDP 20 mg/m(2) on days 1-5). The VP regimen consisted of VDS and CDDP with the same dose and schedule as the VIP regimen. Both regimens were repeated every 4 weeks. Objective response rates were 49.3% (95% confidence interval: 95%CI, 43.1-55.4%) in the VIP arm and 44.6% (95%CI, 38.4-50.2%) in the VP arm; the difference was not significant (P=0.5390). Median response duration, median survival time, and two-year survival rates were 26.5 weeks, 49.6 weeks, and 14.9% in the VIP arm and 28.7 weeks, 37.1 weeks, and 12.3% in the VP arm, respectively. There were also no significant differences between these two treatment arms. In comparison with the VP regimen, however, a survival advantage of the VIP regimen could be confirmed when the data were evaluated with Cox's multivariate analysis (P=0.0131). In both arms, the principal toxicity was myelosuppression, which was significantly more frequent in the VIP arm, although generally well tolerated.

CONCLUSION

This study suggested the survival advantage of the VIP regimen over the VP regimen for treatment of patients with advanced NSCLC.

Gingival metastasis in lung cancer

Gingival metastasis is an extremely rare manifestation of lung cancer, and exhibits rapid growth with various clinical symptoms. Physicians must appropriately manage patients with lung cancer who develop gingival metastasis. Clinical records of patients with lung cancer treated at the Department of Internal Medicine II, Okayama University Hospital, between 1976 and 1998 were retrospectively reviewed. The medical literature was searched by Medline to identify reports of gingival metastasis from lung cancer. Three of 729 (0.41%) lung cancer patients developed gingival metastasis in our hospital between 1976 and 1998, and 9 additional cases of this type of metastasis were found in the literature. All were male, and median age was 57.5 years (range, 47 to 70). There were no clear correlations between development of gingival metastasis and either histologic type or location of the primary lesion. Chemotherapy or radiotherapy was effective for treatment of gingival metastasis, and the quality of life was improved. However, survival after development of gingival metastasis was very short, with median survival of only 4 months.

[Combination chemotherapy with carboplatin and etoposide for elderly patients aged 76 years or older with small cell lung cancer]

Eighteen elderly patients aged 76 years or older with small cell lung cancer were treated with carboplatin (AUC = 4 mg/ml.min, i.v. day 1) and etoposide (70 mg/m2 i.v. day 1-3) and 17 patients were evaluable. The median age of the study population was 77 years (range: 76-81). Eight patients had limited disease (LD) and nine did extensive disease (ED). The overall response rate was 88% for LD patients and 67% for ED patients. Median survival time was 219 days for LD patients and 158 days for ED patients. Grade 3 and 4 leukopenia, neutropenia, thrombocytopenia and anemia occurred in 41%, 76%, 24% and 6% of patients, respectively. There was one treatment-related death due to pneumonitis.

Gastric perforation due to metastasis from adenocarcinoma of the lung

We report a rare case of the development of gastric perforation at the site of metastasis from adenocarcinoma of the lung during systemic chemotherapy. We speculated that the chemotherapy-induced necrosis of the metastatic tumor might have led to the gastric perforation. To the best of our knowledge, this is the first case of chemotherapy-induced gastric perforation as a complication of lung cancer treatment.

Characterization of non-small-cell lung cancer cell lines established before and after chemotherapy

We established several in vitro drug-resistant cell lines after continuous, long-term exposure of each drug to elucidate mechanisms of drug resistance. Whether drug resistance in these in vitro resistant cell lines reflects clinical drug resistance still remains unanswered. In this study, a pair of lung cancer cell lines was established from one patient with squamous cell carcinoma of the lung, with one line being established before and one line after combination chemotherapy (cisplatin/ifosfamide/vindesine). Combination chemotherapy selected resistant EBC-2/R cells, which showed cross-resistance to 4-hydroxyifosfamide (3.2-fold), cisplatin (2.3-fold), and methotrexate (3.7-fold) and collateral sensitivity to vindesine (0.77-fold) compared with parent EBC-2 cells. EBC-2/R cells showed decrease in intracellular accumulation of cisplatin, increase in intracellular concentration of glutathione (GSH), and overexpression of multidrug resistance-associated protein (MRP) 3 when compared with EBC-2 cells. A single cycle of chemotherapy was not sufficient to select other mechanisms of drug resistance, such as multidrug resistance-1/P-glycoprotein, MRPs 1, 2, 4, and 5, lung resistance-related protein, metallothionein IIa, glutathione S-transferase pi, gamma-glutamylcysteine synthetase (light and heavy chain), and excision repair cross complementing 1. Sequentially we established two cell lines, which cell lines showed the differences of the cisplatin resistance, expression level of MRP3, intracellular GSH level and intracellular accumulation of cisplatin. A pair of cell lines will be useful to elucidate resistant mechanisms of cisplatin in heterogeneous lung cancer cells.

Primary signet-ring cell carcinoma of the lung with histochemical characterization

Signet-ring cell carcinoma (SRCC) is a unique sub-type of mucin-producing adenocarcinoma characterized by abundant intracellular mucin accumulation. Although SRCC has been found in various organs, to the best of our knowledge there have only been a few reports of primary SRCC of the lung. Furthermore, most of the reports describe the coexistence of SRCC with differentiated components, while only one case has been reported as pure SRCC. We report here on a patient with primary SRCC of the lung with histochemical characterization. In our case, the tumor cells were mostly composed of signet-ring cells. Although the patient achieved only a minor response after systemic chemotherapy, he has been doing well, without any further treatment, for 33 months after diagnosis.

Interleukin-12 augments cytolytic activity of peripheral blood mononuclear cells against autologous lung cancer cells in combination with IL-2

The majority of patients with advanced lung cancer die within a few years. Accordingly, new therapeutic modalities need to be developed. Interleukin (IL)-12 was previously known as natural killer (NK) cell stimulatory factor or cytotoxic lymphocyte maturation factor. By virtue of its effects on T cells and NK cells, IL-12 seems to be one of the key cytokines that regulates cell-mediated anti tumor immune responses. Recently, there has been a substantial interest in the potential applications of IL-12 in the treatment of lung cancer. However, there have been no reports about the effect of IL-12 on peripheral blood mononuclear cells (PBMCs) obtained from lung cancer patients in an autologous setting. In this study, we examined the cytotoxicity of PBMC activated by IL-2, IL-12 or both against K562 or autologous lung cancer cells. In contrast to the effect of IL-2 on NK activity, IL-12 alone augmented NK activity against K562 cells, but not against autologous lung cancer cells. IL-12 augmented the IL-2 mediated cytotoxicity of PBMC against both K562 and autologous lung cancer cells. In the absence of IL-2, IL-12 alone cannot induce an autologous anti-tumor effect in vivo. In summary, our results clearly demonstrated that IL-12 can augment the cytolytic activity of PBMC against K562 and autologous lung cancer cells when combined with IL-2, although, IL-12 alone was unable to induce a marked increase in the cytotoxicity against autologous lung cancer cells. These results suggest that an administration of IL-12 in combination with IL-2 may be a useful therapeutic option for solid tumors.

Preoperative induction chemotherapy with cisplatin and irinotecan for pathological N(2) non-small cell lung cancer

We conducted a phase I/II study to investigate whether the surgical resection after induction chemotherapy with cisplatin and irinotecan was feasible and could improve the treatment outcome for patients with pathological N(2) non-small cell lung cancer. Fifteen patients with stage IIIA non-small cell lung cancer having mediastinal lymph node metastases proved by mediastinoscopy were eligible. Both cisplatin (60 mg m(-2)) and irinotecan (50 mg m(-2)) were given on days 1 and 8. Patients received two cycles of chemotherapy after 3-4 weeks interval. Induction was followed by surgical resection in 4-6 weeks. Patients who had documented tumour regression after preoperative chemotherapy received two additional cycles of chemotherapy and other patients received radiotherapy postoperatively. After the induction chemotherapy, the objective response rate was 73%. All the 15 patients received surgical resection and complete resection was achieved in 11 (73%) patients. There was no operation-related death and one death due to radiation pneumonitis during postoperative radiotherapy. The median time from entry to final analysis was 46.5 months, ranging from 22 to 68 months. The 5-year survival rate was 40% for all the 15 patients and it was 55% for the 11 patients who underwent complete resection. We conclude that the surgical resection after induction chemotherapy with cisplatin and irinotecan is feasible, and associated with low morbidity and high respectability.

Spontaneous regression of metastatic endometrial stromal sarcoma

Spontaneous regression of malignancy is rare and there appear to be no reports of spontaneous regression of endometrial stromal sarcoma. We report a rare case of metastatic endometrial stromal sarcoma that regressed spontaneously. A 58-year-old woman was admitted to hospital in January 1996 when her chest radiograph showed multiple nodular shadows in the left lower lung field. Computed tomography of the chest revealed bilateral nodules. Segmentectomy of the left lower lobe was performed by thoracoscopy. She had a past history of uterine myoma with metrorrhagia for which she had undergone a hystero-oophorectomy 10 years earlier. She also had a vaginal polyp removed 1 year earlier. The lung pathology was studied and the surgical specimens of the uterus and vagina were re-examined. The diagnosis was endometrial stromal sarcoma primarily arising in the uterus. The vaginal polyp and the pulmonary nodules were considered to be metastases. Samples of lung and vaginal tissues were positive for both estrogen and progesterone receptors. The patient was discharged without treatment in February 1996 and followed up in the outpatient clinic. The tumor shadow measuring 2 mm in diameter on admission was enlarged to 4 mm in diameter 1 year later. Surprisingly, spontaneous regression of the lung disease occurred at 33 months, the tumor size decreasing to 2 mm in diameter and to 1 mm at 46 months. No evidence of tumor enlargement was detected at the last follow-up in July 2001. Although the precise mechanism of tumor regression is unknown, metastatic endometrial stromal sarcoma may spontaneously regress.

Polymorphisms of UDP-glucuronosyltransferase and pharmacokinetics of irinotecan

Irinotecan is a prodrug that is hydrolyzed by carboxylesterase in vivo to form an active metabolite SN-38. SN-38 is further conjugated and detoxified by UDP-glucuronosyltransferase (UGT) to yield its beta-glucuronide (SN-38G). Although irinotecan is widely used, the drug causes unpredictably severe, occasionally fatal, toxicity of leukopenia or diarrhea. Interindividual variation of sensitivity to irinotecan is related to large variations of biotransformation of the active metabolite SN-38, some of which would be caused by genetic polymorphism of UGT1A1, an isozyme responsible for the SN-38 glucuronidation. As a surrogate for the UGT activity, the polymorphic frequency distribution of the area under the concentration-time curve (AUC) ratios of SN-38 to SN-38G (AUC(SN-38)/AUC(SN-38G)) using pooled pharmacokinetic data from four independent study groups in Japan was explored. The data from 100 cancer patients was analyzed, including 14 who were genotyped for UGT1A1 gene in the previous studies. The median ratios of AUC(SN-38)/AUC(SN-38G) was 0.40 (interquartile range, 0.30 to 0.55; range, 0.09 to 2.32). Frequency distribution of the AUC (SN-38)/AUC(SN-38G) was skewed to the right without bimodality and the patient population could not be segregated into discrete subgroups that differ in the UGT activity by the AUC ratios. The 4 subjects carrying UGT1A1*28 allele had values of the AUC(SN-38)/AUC(SN-38G) above the 75th percentile of the total population, suggesting a potential pharmacogenetic/pharmacokinetic relationship. Ordinary values with a median of 0.41 (interquartile range, 0.33 to 0.49) were obtained for the UGT1A1*6 heterozygous patient and the 9 UGT1A1*1 homozygous patients (the reference sequence). The large variation in the UGT activity being related to the genetic status would warrant pharmacogenetic-guided dosing of irinotecan.

Synergistic effects of topoisomerase I inhibitor, 7-ethyl-10-hydroxycamptothecin, and irradiation in a cisplatin-resistant human small cell lung cancer cell line

7-ethyl-10-[4-(1-piperidyl)-1-piperidyl] carbonyloxy-camptothecin, a topoisomerase I (topo I) inhibitor, is one of the most active agent against lung cancer, and its radiosensitizing effect has been reported recently. We evaluated a combination in vitro effect of irradiation and 7-ethyl-10-hydroxy-CPT (SN-38), an active metabolite of 7-ethyl-10-[4- (1-piperidyl)-1-piperidyl] carbonyloxy-camptothecin, on a human small cell lung cancer cell line (SBC-3) and its cisplatin-resistant subline (SBC-3/CDDP). Growth-inhibitory effects of irradiation with or without SN-38 were determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. A modified isobologram method was used to evaluate the treatment interaction. The combination of irradiation and SN-38 showed a synergistic inhibitory effect on the growth of SBC-3/CDDP despite its cross-resistance to irradiation and SN-38. In contrast, the same combination showed only an additive effect on the growth of parental SBC-3 cells. There was no significant difference in topo I protein expression between these two cell lines. In SBC-3 cells, topo I catalytic activity was suppressed by 4 Gy of irradiation, without a decrease of nuclear topo I protein, whereas the exposure of SBC-3 cells to 1 microM SN-38 subsequent to irradiation showed no remarkable additional effects on both topo I activity and protein content. On the other hand, in SBC-3/CDDP cells, topo I activity was unchanged by irradiation, but the subsequent exposure to SN-38 gave rise to a decrease in topo I activity, which was accompanied by a significant decrease in the topo I protein content (P = 0.02). These observations may indicate that SN-38 induces sequestration of topo I onto DNA in radiation-treated SBC-3/CDDP cells and suggest that the synergistic effect of irradiation and SN-38 in SBC-3/CDDP cells was considered attributable to DNA repair-related enhanced recruitment of topo I onto the damaged DNA.

A case-control study of lung cancer screening in Okayama Prefecture, Japan

The effectiveness of lung cancer screening in reducing mortality still remains uncertain. In order to evaluate the efficacy of lung cancer screening, a case-control study was conducted in Okayama Prefecture, Japan. The study area consisted of 34 municipalities where a population-based lung cancer screening had been conducted. Chest X-ray examinations for all participants and sputum cytology for high-risk participants were offered annually. The cases analyzed in this study consisted of 412 individuals aged between 40 and 79 who died of lung cancer. A total of 3490 controls, two to ten for each case matched by gender, year of birth, and living district were randomly collected. Screening histories of cases were compared with those of and matched controls for the identical calendar period prio to diagnosis of the case. Smoking adjusted odds ratio (OR) of death from lung cancer for screened individuals versus unscreened, within 12 months before diagnosis, was calculated as 0.59 (95% confidence interval: 0.46-0.74; P=0.0001). The OR for women (0.39, 95% confidence interval: 0.24-0.64) was lower than that for men (0.67, 95% confidence interval: 0.51-0.87), although both were statistically significant. These results suggest that lung cancer screening contributes to reducing lung cancer mortality by 41%.