Integration of new chemotherapeutic agents into chemoradiotherapy for stage III non--small cell lung cancer: focus on docetaxel

Carbonic anhydrase IX expression in prostate cancer

Tumour hypoxia is associated with over 70% of solid tumours including prostate and colorectal cancer. Hypoxia promotes tumour progression and resistance to treatment. Carbonic anhydrase IX (CA IX) is an endogenous marker of hypoxia. It is expressed in lung and renal cell carcinomas and is associated with a poor prognosis. CA IX has an important role in maintaining pH levels in the highly metabolically active cancer cell. The expression of CA IX in prostate cancer has not previously been investigated. Immunohistochemistry was used to examine CA IX expression in 59 patients, using tissue microarrays (TMAs) and full sections of BPH, surrounding stroma and prostate adenocarcinoma. Cores reviewed included 189 BPH, 130 Gleason grade 3, 93 Gleason grade 4, 40 Gleason grade 5. CA IX expression in colorectal cancer and HIF 1alpha in prostate cancer acted as positive controls. There was only occasional cell staining for CA IX expression. Although prostate cancer is a hypoxic tumour it does not express CA IX. This implies it relies on alternative pathways for maintaining pH balance in cancer. These studies would indicate that CA IX is not a suitable marker of hypoxia in prostate cancer.

Concurrent chemoradiation strategies in the management of unresectable stage III non-small-cell lung cancer

Locally advanced or unresectable stage III non-small-cell lung cancer (NSCLC) patients treated with combined-modality therapy with chemotherapy plus thoracic radiation have improved survival compared to those treated with radiotherapy alone. Furthermore, recent studies in good performance status, stage III patients have shown that concurrent chemoradiotherapy improves survival compared to sequential chemoradiotherapy. However, the optimal chemoradiation approach continues to evolve and is the subject of this review. Since the majority of patients completing chemoradiotherapy will succumb to distant metastatic disease, active systemic agents targeting this tumor compartment are required. Recent data suggest that full-dose chemotherapy designed to eradicate distant micrometastases given either as induction or consolidation has the potential to yield improved patient outcomes. Many of these chemotherapeutic agents are also potent radiosensitizers, hence providing enhanced local control. The integration of these chemotherapeutic agents into chemoradiotherapy programs in stage III NSCLC is the focus of current trials. Ongoing research with novel therapeutic agents with activity against distant micrometastases, refined radiation techniques, and enhanced imaging methodologies to aid in accurate staging are being pursued and should lead to improved survival and toxicity outcomes in this disease.

Docetaxel-based combined-modality chemoradiotherapy for locally advanced non-small cell lung cancer

The cytotoxic agent docetaxel not only has proven activity in non-small cell lung cancer-when used alone or in combination-but is also a potent radiosensitizer, and improved treatments are needed in all stages of this disease. In patients with locoregionally advanced (stage III) disease, docetaxel has shown efficacy with manageable toxicities when used alone or in combination with a platinum compound in a sequential manner before localized radical radiotherapy/surgery. Presently, therapeutic gains appear to be maximized by the use of concurrent chemotherapy and irradiation. This review focuses on research with combinations of docetaxel with either cisplatin or carboplatin and radiotherapy. Overall response and survival rates to date provide data worth pursuing. From phase I data, weekly docetaxel at 20 mg/m(2) plus cisplatin at 25 mg/m(2) or carboplatin to an area under the concentration time curve of 2 mg/ml*min with concurrent radiotherapy to 60 Gy over 6 weeks appear to be suitable for phase II trials. Predominant toxicities are esophagitis and neutropenia, but a low frequency of pulmonary toxicity is reported. Induction, concurrent, and consolidation docetaxel-based chemoradiotherapy in potentially resectable disease are all being investigated. Future research could include the investigation of computed tomography/ positron emission tomography-derived target volume radiotherapy, dose-escalated therapy, and alternative fractionation schedules in combination with docetaxel-based cytotoxic chemotherapy.

Phase I/II study of docetaxel and cisplatin with concurrent thoracic radiation therapy for locally advanced non-small-cell lung cancer

Recent studies have suggested the superiority of concomitant over sequential administration of chemotherapy and radiotherapy. Docetaxel and cisplatin have demonstrated efficacy in advanced non-small-cell lung cancer (NSCLC). This study evaluated the safety, toxicity, and antitumour activity of docetaxel/cisplatin with concurrent thoracic radiotherapy for patients with locally advanced NSCLC. Patients with locally advanced NSCLC (stage IIIA or IIIB), good performance status, age <or=75 years, and adequate organ function were eligible. Both docetaxel and cisplatin were given on days 1, 8, 29, and 36. Doses of docetaxel/cisplatin (mg m(-2)) in the phase I study portion were escalated as follows: 20/30, 25/30, 30/30, 30/35, 30/40, 35/40, 40/40, and 45/40. Beginning on day 1 of chemotherapy, thoracic radiotherapy was given at a total dose of 60 Gy with 2 Gy per fraction over 6 weeks. In the phase I portion, the maximum tolerated doses (MTD) among 33 patients were docetaxel 45 mg m(-2) and cisplatin 40 mg m(-2). The major dose-limiting toxicity (DLT) was radiation oesophagitis. The recommended doses (RDs) for the phase II study were docetaxel 40 mg m(-2) and cisplatin 40 mg m(-2). A total of 42 patients were entered in the phase II portion. Common toxicities were leukopenia, granulocytopenia, anaemia, and radiation oesophagitis, with frequencies of grade >or=3 toxicities of 71, 60, 24, and 19%, respectively. Toxicity was significant, but manageable according to the dose and schedule modifications. Dose intensities of docetaxel and cisplatin were 86 and 87%, respectively. Radiotherapy was completed without a delay in 67% of 42 patients. The overall response rate was 79% (95% confidence interval (CI), 66-91%). The median survival time was 23.4+ months with an overall survival rate of 76% at 1 year and 54% at 2 years. In conclusion, chemotherapy with cisplatin plus docetaxel given on days 1, 8, 29, and 36 and concurrent thoracic radiotherapy is efficacious and tolerated in patients with locally advanced NSCLC and should be evaluated in a phase III study.

Taxotere resistance in SUIT Taxotere resistance in pancreatic carcinoma cell line SUIT 2 and its sublines

AIM: To investigate the specific mechanisms of intrinsic and acquired resistance to taxotere (TXT) in pancreatic adenocarcinoma (PAC).

METHODS: MTT assay was used to detect the sensitivity of PAC cell line SUIT-2 and its sublines (S-007, S-013, S-020, S-028 and TXT selected SUIT-2 cell line, S2/TXT) to TXT. Mdr1 (P-gp), multidrug resistance associated protein (MRP), lung resistance protein (LRP) and β-tubulin isotype gene expressions were detected by RT-PCR. The functionality of P-gp and MRP was tested using their specific blocker verapamil (Ver) and indomethacin (IMC), respectively. The transporter activity of P-gp was also confirmed by Rhodamine 123 accumulation assay.

RESULTS: S-020 and S2/TXT were found to be significantly resistant to TXT (19 and 9.5-fold to their parental cell line SUIT-2, respectively). RT-PCR demonstrated strong expression of Mdr1 in these two cell lines, but weaker expression or no expression in other cells lines. MRP and LRP expressions were found in most of these cell lines. The TXT-resistance in S2-020 and S2/TXT could be reversed almost completely by Ver, but not by IMC. Flow cytometry showed that Ver increased the accumulation of Rhodamine-123 in these two cell lines. Compared with S-020 and SUIT-2, the levels of β-tubulin isotype II, III expressio ns in S-2/TXT were increased remarkably.

CONCLUSION: The both intrinsic and acquired TXT-related drug resistance in these PAC cell lines is mainly mediated by P-gp, but had no relationship to MRP and LRP express ions. The increases of β-tubulin isotype II, III might be collateral changes that occur when the SUIT-2 cells are treated with TXT.