Combined chemotherapy and radiation in locally advanced non-small-cell lung cancer

DNA radiosensitization by terpyridine-platinum: damage induced by 5 and 10 eV transient anions

Chemoradiation therapy (CRT), which combines a chemotherapeutic drug with ionizing radiation (IR), is the most common cancer treatment. At the molecular level, the binding of Pt-drugs to DNA sensitizes cancer cells to IR, mostly by increasing the damage induced by secondary low-energy (0-20 eV) electrons (LEEs). We investigate such enhancements by binding terpyridine-platinum (Tpy-Pt) to supercoiled plasmid DNA. Fifteen nanometer thick films of Tpy-Pt-DNA complexes in a molar ratio of 5 : 1 were irradiated with monoenergetic electrons of 5 and 10 eV, which principally attach to the DNA bases to form transient anions (TAs) decaying into a multitude of bond-breaking channels. At both energies, the effective yields of crosslinks (CLs), base damage (BD) related CLs, single and double strand breaks (SSBs and DSBs), non-DSB-cluster lesions, loss of supercoiled configuration and base lesions are 6.5 ± 1.5, 8.8± 3.0, 88 ± 11, 5.3 ± 1.3, 9.6 ± 2.2, 106 ± 17, 189 ± 31 × 10^-15 per electron per molecule, and 11.9 ± 2.6, 19.9 ± 4.4, 128 ± 18, 7.7 ± 3.0, 13.4 ± 3.9, 144 ± 19, 229 ± 42 × 10^-15 per electron per molecule, respectively. DNA damage increased 1.2-4.2-fold due to Tpy-Pt, the highest being for BD-related CLs. These enhancements are slightly higher than those obtained by the conventional Pt-drugs cisplatin, carboplatin and oxaliplatin, apart from BD-related CLs, which are about 3 times higher. Enhancements are related to the strong perturbation of the DNA helix by Tpy-Pt, its high dipole moment and its favorable binding to guanine (G), all of which increase bond-breaking via TA formation. In CRT, Tpy-Pt could considerably enhance crosslinking within genomic DNA and between DNA and other components of the nucleus, causing roadblocks to replication and transcription, particularly within telomeres, where it binds preferentially within G-quadruplexes.

I-125 seeds with chemotherapy for progressive non-small-cell lung cancer after first-line treatment: a meta-analysis

Background

Continuing therapy for aggressive non-small-cell lung cancer (NSCLC) after first-line treatment (FLT) is challenging. The clinical efficacy of second-line chemotherapy (SLCT) for progressive NSCLC is limited. In this meta-analysis, we aim to evaluate the clinical efficacy of the combination of I-125 seeds brachytherapy (ISB) and SLCT in progressive NSCLC after FLT.

Methods

The PubMed, Embase, Cochrane Library, CNKI, Wanfang, and VIP databases were screened for relevant publications until September 2021. Meta-analyses are conducted by RevMan 5.3 and Stata 12.0.

Results

Our meta-analysis encompassed 6 studies (4 retrospective studies and 2 randomized controlled trials), which included 272 patients that underwent ISB with SLCT (combined group) and 257 patients that received SLCT alone (chemotherapy alone group). The complete response (24.7% vs. 7.0%, P < 0.00001), treatment response (65.7% vs. 38.1%, P = 0.0002), and disease control (95.2% vs. 80.4%, P < 0.00001) rates are markedly elevated for patients receiving combined therapy versus those receiving chemotherapy alone. Moreover, pooled progression-free survival (P = 0.0001) and overall survival (P < 0.00001) were remarkably extended for patients that received the combination therapy, while no obvious differences were detected in the pooled myelosuppression (39.0% vs. 30.6%, P = 0.05) and gastrointestinal response (38.5% vs. 35.9%, P = 0.52) rates between 2 groups. Significant heterogeneity was found in the endpoints of the treatment response and progression-free survival.

Conclusions

This meta-analysis demonstrated that ISB could enhance the clinical efficacy of SLCT in patients with progressive NSCLC after FLT without inducing major toxic side effects.

The Clinical Value of Computed Tomography (CT)-Guided 125I Brachytherapy for Locally Advanced Non-Small Cell Lung Cancer After Progression of Concurrent Radiochemotherapy

Purpose

To further evaluate the efficacy and safety of computed tomography (CT)-guided iodine 125 (¹²⁵I) brachytherapy to treat locally advanced non-small cell lung cancer (NSCLC) after progression of concurrent radiochemotherapy (CCRT).

Methods

This study obtained written consent from all patients and was approved by our institution. From January 2006 to June 2018, 210 NSCLC patients (progression of first-line CCRT) were retrospectively recruited and then divided into two groups. A total of 116 patients were given CT-guided ¹²⁵I brachytherapy and second-line chemotherapy (group A), and 94 were treated with second-line chemotherapy alone (group B).

Results

In group A, local response rate (LRR) within 3 years was significantly better (P<0.05). Mean survival time [progression-free survival time (PFST) and overall survival (OS)] was 15.1±1.4 months and 21.2±1.6 months in group A compared with 10.0±1.4 months and 16.2±1.7 months in group B (PFST: P<0.01, HR=1.472, 95% CI 1.097–1.975; OS: P = 0.036, HR=1.342, 95% CI 1.005–1.791). Tumor size and No. of first cycle chemotherapy were independent factors that affected survival, ≤3cm largest tumor diameter and more than 4 first cycles of chemotherapy showed longer PFST and OS (P<0.05). Tumor-related clinical symptoms were relieved in group A (P<0.01). No serious complications occurred in the two groups.

Conclusion

¹²⁵I brachytherapy is effective and safe in locally advanced NSCLC after progression of CCRT.

A phthalimidoalkanamide derived novel DNMT inhibitor enhanced radiosensitivity of A549 cells by inhibition of homologous recombination of DNA damage

Purpose To elucidate the radiosensitizing effect and underlying mechanism of a new kind of DNA methyltransferase (DNMT) inhibitor with biological availability. Methods A novel non-nucleoside compound, designated as MA-17, was recently derived from a phthalimido alkanamide structure. DNMT expressions were confirmed in cultured human lung cancer (A549) and normal astrocyte (NHA) cells, radiosensitivity was measured using clonogenic assay, and assays of cell cycle alteration, apoptosis, DNA damage repair, and differential gene expression were undertaken. Results MA-17 significantly radiosensitized A549 cells with a mean dose enhancement ratio (DER) of 1.43 at the surviving fraction of 0.2 (p < 0.05 by one-tailed ratio paired t-test). MA-17 did not affect normal astrocytes (mean DER_0.2, 1.016; p = 0.420). MA-17 demonstrated a mean half-life of 1.0 h in vivo and a relatively even distribution in various tissues. Pretreatment with MA-17 increased sub-G1 fractions and inhibited the repair of DNA double-strand breaks, which are induced by irradiation. We found that MA-17 also down-regulated DNA homologous recombination and the Fanconi anemia pathway (FANCA, BRCA1, and RAD51C) in A549 cells. This bioinformatics finding was confirmed in validation Western blot to evaluate the expression of vital proteins. Conclusions A novel phthalimido alkanamide derivative, a DNMT inhibitor, possessed both biostability and favorable and substantial radiosensitizing effects by augmenting apoptosis or inhibiting DNA damage repair.

Modern Radiation Further Improves Survival in Non-Small Cell Lung Cancer: An Analysis of 288,670 Patients

Background: Radiation therapy plays an increasingly important role in the treatment of patients with non-small-cell lung cancer (NSCLC). The purpose of the present study is to assess the survival outcomes of radiotherapy treatment compared to other treatment modalities and to determine the potential role of advanced technologies in radiotherapy on improving survival. Methods: We used cancer incidence and survival data from the Surveillance, Epidemiology, and End Results database linked to U.S. Census data to compare survival outcomes of 288,670 patients with stage I-IV NSCLC treated between 1999 and 2008. The primary endpoint was overall survival. Results: Among the 288,670 patients diagnosed with stage I-IV NSCLC, 92,374 (32%) patients received radiotherapy-almost double the number receiving surgery (51,961, 18%). Compared to other treatment groups and across all stages of NSCLC, patients treated with radiotherapy showed greater median and overall survival than patients without radiation treatment (p < 0.0001). Radiotherapy had effectively improved overall survival regardless of age, gender, and histological categorization. Radiotherapy treatment received during the recent time period 2004 - 2008 is correlated with enhanced survival compared to the earlier time period 1999 - 2003. Conclusion: Radiation therapy was correlated with increased overall survival for all patients with primary NSCLC across stages. Combined surgery and radiotherapy treatment also correlates with improved survival, signaling the value of bimodal or multimodal treatments. Population-based increases in overall survival were seen in the recent time period, suggesting the potential role of advanced radiotherapeutic technologies in enhancing survival outcomes for lung cancer patients.

Chemoradiotherapeutic Magnetic Nanoparticles for Targeted Treatment of Nonsmall Cell Lung Cancer

Lung cancer is the leading cause of cancer-related death in the United States and approximately 85% of all lung cancers are classified as nonsmall cell (NSCLC). We here use an innovative approach that may ultimately allow for the clinician to target tumors and aggressively reduce tumor burden in patients with NSCLC. In this study, a platinum (Pt)-based chemotherapeutic (cisplatin, carboplatin, or oxaliplatin) and holmium-165 (Ho), which can be neutron-activated to produce the holmium-166 radionuclide, have been incorporated together in a garnet magnetic nanoparticle (HoIG-Pt) for selective delivery to tumors using an external magnet. The synthesized magnetic HoIG nanoparticles were characterized using PXRD, TEM, ICP-MS, and neutron-activation. Platinum(II) drugs were incorporated onto HoIG, and these were characterized using FTIR, EDX, ICP-MS, and zeta potential measurements, and in vitro and in vivo studies were performed using a HoIG-platinum system. Results indicate that neutron-activated (166)HoIG-cisplatin is more toxic toward NSCLC A549 cells than is blank (166)HoIG and free cisplatin, and that when an external magnetic field is applied in vivo, higher tumor to liver ratios of Ho are observed than when no magnet is applied, suggesting that magnetic targeting is achieved using this system. Furthermore, an efficacy study demonstrated the inhibition of tumor growth by chemoradiotherapeutic magnetic nanoparticles, compared to no treatment controls.

Indoleamine 2,3-dioxygenase mediates immune-independent human tumor cell resistance to olaparib, gamma radiation, and cisplatin

Indoleamine 2,3-dioxygenase-1 (IDO) is an immunosuppressive molecule expressed by most human tumors. IDO levels correlate with poor prognosis in cancer patients and IDO inhibitors are under investigation to enhance endogenous anticancer immunosurveillance. Little is known of immune-independent functions of IDO relevant to cancer therapy. We show, for the first time, that IDO mediates human tumor cell resistance to a PARP inhibitor (olaparib), gamma radiation, cisplatin, and combined treatment with olaparib and radiation, in the absence of immune cells. Antisense-mediated reduction of IDO, alone and (in a synthetic lethal approach) in combination with antisense to the DNA repair protein BRCA2 sensitizes human lung cancer cells to olaparib and cisplatin. Antisense reduction of IDO decreased NAD⁺ in human tumor cells. NAD⁺ is essential for PARP activity and these data suggest that IDO mediates treatment resistance independent of immunity and at least partially due to a previously unrecognized role for IDO in DNA repair. Furthermore, IDO levels correlated with accumulation of tumor cells in G₁ and depletion of cells in G₂/M of the cell cycle, suggesting that IDO effects on cell cycle may also modulate sensitivity to radiation and chemotherapeutic agents. IDO is a potentially valuable therapeutic target in cancer treatment, independent of immune function and in combination with other therapies.

RNA-seq profiling of a radiation resistant and radiation sensitive prostate cancer cell line highlights opposing regulation of DNA repair and targets for radiosensitization

BACKGROUND

Radiotherapy is a chosen treatment option for prostate cancer patients and while some tumours respond well, up to 50% of patients may experience tumour recurrence. Identification of functionally relevant predictive biomarkers for radioresponse in prostate cancer would enable radioresistant patients to be directed to more appropriate treatment options, avoiding the side-effects of radiotherapy.

METHODS

Using an in vitro model to screen for novel biomarkers of radioresistance, transcriptome analysis of a radioresistant (PC-3) and radiosensitive (LNCaP) prostate cancer cell line was performed. Following pathway analysis candidate genes were validated using qRT-PCR. The DNA repair pathway in radioresistant PC-3 cells was then targeted for radiation sensitization using the PARP inhibitor, niacinimide.

RESULTS

Opposing regulation of a DNA repair and replication pathway was observed between PC-3 and LNCaP cells from RNA-seq analysis. Candidate genes BRCA1, RAD51, FANCG, MCM7, CDC6 and ORC1 were identified as being significantly differentially regulated post-irradiation. qRT-PCR validation confirmed BRCA1, RAD51 and FANCG as being significantly differentially regulated at 24 hours post radiotherapy (p-value =0.003, 0.045 and 0.003 respectively). While the radiosensitive LNCaP cells down-regulated BRCA1, FANCG and RAD51, the radioresistant PC-3 cell line up-regulated these candidates to promote cell survival post-radiotherapy and a similar trend was observed for MCM7, CDC6 and ORC1. Inhibition of DNA repair using niacinamide sensitised the radioresistant cells to irradiation, reducing cell survival at 2 Gy from 66% to 44.3% (p-value =0.02).

CONCLUSIONS

These findings suggest that the DNA repair candidates identified via RNA-seq hold potential as both targets for radiation sensitization and predictive biomarkers in prostate cancer.

CT-guided implantation of radioactive 125I seed in advanced non-small-cell lung cancer after failure of first-line chemotherapy

PURPOSE

We investigated implanting computed tomography (CT)-guided (125)I seed to treat locally advanced non-small-cell lung cancer (NSCLC) after chemotherapy failure.

METHODS

From January 2005 to July 2010, we recruited 69 patients with locally advanced NSCLC who had each had first-line chemotherapy four to six times but had progressive disease; 34 received (125)I seed implantation with second-line chemotherapy (Group A) and 35 received second-line chemotherapy only (Group B).

RESULTS

Mean follow-up was 32 months (range 5-56 months). Overall 2-year local control rate for existing lung lesions was Group A: 39.9 %; Group B: 12.5 % (P < 0.05). The 1-, 3-year, and median overall survival was 68.7 and 20.8 % at 17.4 months in Group A; and 45.1 and 18.7 % at 11.3 months in Group B, respectively (P > 0.05). Local 3-, 24-month, and median progression-free survival was Group A: 100 and 79.1 % at 11 months; Group B: 76.5 and 18.7 % at 7.3 months, respectively. The groups did not significantly differ in treatment toxicity. Chest pain remission was Group A: 82.1 % (23/28); Group B: 30.8 % (8/26) (P < 0.05). Group A showed no radiation-related pneumonia, esophagitis, bronchial fistulae, or life-threatening morbidity.

CONCLUSION

CT-guided radioactive seed (125)I implantation procedure is safe and well tolerated in treating locally advanced NSCLC, with few complications. It has good local control rate and can relieve symptoms without increasing side effects.

Outcomes of patients with unresected stage III and stage IV non-small cell lung cancer: A single institution experience

Introduction:

To report on the demographic profile and survival outcomes of North Indian population affected with stage III and stage IV non-small cell lung cancer (NSCLC).

Materials and Methods:

From November 2008 to January 2012, 138 consecutively diagnosed NSCLC patients were included in this study. The patient, tumor and treatment related factors were analyzed. Median overall survival (OS), Kaplan-Meier survival plots, t-test, Cox proportional hazards models were generated by multivariate analysis [MVA]) and analyzed on SPSS software (version 19.0; SPSS, Inc., Chicago, IL).

Results:

Median OS of stage III patients was 9.26 ± 1.85 months and 2-year survival rate of 13% while stage IV patients had median OS of 5 ± 1.5 months with a 2-year survival rate of 8%. Cox regression modeling for MVA demonstrated higher biologically equivalent dose (BED) (P = 0.01) in stage III while in stage IV non-squamous histology (P = 0.01), administration of chemotherapy (P = 0.02), partial responders to chemotherapy (P = 0.001), higher BED (P = 0.02), and those with skeletal metastasis alone (P = 0.17) showed a better OS.

Conclusion:

Our data showed that a higher BED is associated with favorable outcomes, indicating a role of dose escalated radiation therapy to the primary lesion in both stage III and essentially in stage IV NSCLC. Additionally, optimal use of chemotherapy relates to better survival. The developing, resource restrained nations need to follow an economically feasible multimodality approach.

Isolated lung perfusion with gemcitabine combined with radiotherapy: no additional lung toxicity in an experimental model

OBJECTIVES

Isolated lung perfusion with gemcitabine is an effective technique for the treatment of lung metastases in an experimental model. In clinical studies, increased toxicity has been observed when combining intravenous gemcitabine with radiotherapy (RT). The goal of our study was to determine whether RT in combination with isolated lung perfusion increases lung toxicity.

METHODS

Rodents were randomized into eight groups: sham group, RT, intravenous gemcitabine, intravenous gemcitabine combined with RT, isolated lung perfusion with hydroxyethyl starch (HES) or gemcitabine, isolated lung perfusion with HES or gemcitabine combined with RT. Gemcitabine was administered in a dose of 40 mg/kg and RT as a single fraction of 8 Gy. The effect on lung tissue was evaluated by % fibrosis in a haematoxylin-eosin stain and by % alveoli that contained siderophages on Perls stain. A total of 36 slices were made per treatment and per stain. The results of different groups were compared using logistic regression.

RESULTS

There were no significant differences between treatment with intravenous gemcitabine and RT. Isolated lung perfusion with gemcitabine showed significant more histopathologic changes compared with intravenous gemcitabine (P < 0.0001). When RT was added, there was no fibrosis after intravenous gemcitabine and mild-to-moderate haemosiderosis. After isolated lung perfusion with gemcitabine combined with RT, there was moderate to severe fibrosis and mild to severe haemosiderosis. Adding RT to isolated lung perfusion with gemcitabine showed no significant difference compared to isolated lung perfusion alone.

CONCLUSIONS

Combination of isolated lung perfusion and RT is feasible in an experimental model. No additional toxicity of RT was observed compared to isolated lung perfusion alone. Further studies are necessary to determine efficacy of this combined treatment.

How to improve loco-regional control in stages IIIa-b NSCLC? Results of a three-armed randomized trial from the Swedish Lung Cancer Study Group

BACKGROUND

A combination of chemotherapy and radiotherapy is the treatment base for locally advanced non-small cell lung cancer (NSCLC). However, both loco-regional and distant failure is frequent. Attempts to improve the loco-regional control were made in three separate phase II studies in Swedish University Hospitals, where accelerated radiotherapy or concurrent daily or weekly chemotherapy with conventional radiotherapy were tested. Comparatively good results from these studies lead to this national randomized phase II study, the RAKET-study, where the different concepts were investigated on a wider basis for further phase III studies.

METHODS

Inoperable stage III non-small cell lung cancer patients in good performance status (PS<2) were equally randomized to either of three arms in eight institutions. All arms started with two cycles of induction chemotherapy: paclitaxel 200 mg/m2 and carboplatin AUC6. Arm A: a third identical cycle was given concomitant with start of accelerated radiotherapy, 1.7 Gy BID to 64.6 Gy in 4.5 weeks. Arm B consisted of daily concomitant paclitaxel 12 mg/m2 with conventionally fractionated radiotherapy: 2 Gy to 60 Gy in 6 weeks. Arm C: weekly concomitant paclitaxel 60 mg/m2 and identical radiotherapy to 60 Gy. Primary endpoint: TTP. Secondary: OS, toxicity, QL and relapse pattern.

RESULTS

Between June 2002 and May 2005 152 patients were randomized and of them 151 were evaluable: 78 men and 73 women, median age 62 years (43-78), 55% had performance status 0 and 45% PS 1. Thirty-four percent had stage IIIa and 66% IIIb.

HISTOLOGY

adenocarcinoma 48%, squamous cell carcinoma 32% and 20% non-small cell carcinoma. The three arms were well balanced. Toxicity was manageable with 12% grades 3-4 esophagitis, 1% grades 3-4 pneumonitis and there was no clear difference between the arms. The QL data did not differ either. Median time to progression was 9.8 (8.3-12.7) months (8.8, 10.3 and 9.3 months for arms A, B and C, respectively). Median survival was 17.8 (14.4-23.7) months (17.7, 17.7 and 20.6 months for A, B and C, respectively). The 1-, 3- and 5-year overall survival was 63, 31 and 24%. Sixty-nine percent of the patients relapsed with distant metastases initially and 31% had loco-regional tumor progression, without significant differences between treatment arms. Thirty-four percent developed brain metastases.

CONCLUSIONS

Treatment results are quite equal by intensifying the loco-regional treatment either by accelerated fractionated radiotherapy or daily or weekly concomitant chemo-radiotherapy both in terms of survival, toxicity and quality of life. The optimal treatment schedule for patients with locally advanced NSCLC is still to be decided and investigated in future clinical studies. Relapse pattern with distant metastases and especially brain metastases is a great problem and need further research for better therapy options and higher cure rate for this patient group.

Combined-modality therapy with gemcitabine and radiation therapy as a bladder preservation strategy: long-term results of a phase I trial

PURPOSE

A Phase I trial of twice-weekly gemcitabine and concurrent radiation therapy (RT) was performed in patients with muscle-invasive bladder cancer. We present the final analysis of bladder-intact survival (BIS), disease-specific survival (DSS), and overall survival (OS).

METHODS AND MATERIALS

Eligible patients had muscle-invasive transitional cell carcinoma (cT2-3) and were candidates for cystectomy. Patients underwent maximal transurethral resection of bladder tumor followed by twice-weekly gemcitabine with concurrent RT to the bladder (total of 60 Gy over 6 weeks). Gemcitabine doses ranged from 10 to 33 mg/m(2).

RESULTS

Median follow-up was 5.6 years (range, 0.6-9.5 years). Twenty-three of 24 patients were evaluable for response. All patients were clinical stage T2. Locoregional failure occurred in seven patients (30%), which were successfully salvaged by radical cystectomy (n = 5) or intravesical therapy (n = 2). Four local failures occurred > 5 years after therapy. Most local failures were noninvasive tumors (Ta or Tis, n = 6). Ten patients (43%) experienced optimal outcome (no failures and bladder intact). The 5-year actuarial estimates of survival are BIS 62%, OS 76%, and DSS 82%.

CONCLUSION

Twice-weekly gemcitabine with concurrent RT is well tolerated and provides rates of survival and bladder preservation that are comparable to the existing literature. All locoregional failures were successfully salvaged by either radical cystectomy or intravesical therapy. Given the high proportion of late local failures, we recommend long-term monitoring when using this regimen. Future studies comparing the safety and efficacy of gemcitabine- vs. platinum-based bladder preservation protocols are pending.

The role of radiotherapy in lung cancer: Where is the evidence?

Radiotherapy is one of the main treatment modalities in lung cancer, contributing to both its cure and palliation. Thoracic irradiation has traditionally been considered the mainstay of treatment in inoperable stage III non-small cell lung cancer. However, despite technical developments and the addition of chemotherapy, the curative potential of radiotherapy in this subset of patients is disappointingly poor. The role of radiotherapy as an adjunct to pulmonary resection (preoperative and postoperative) is questionable, but well-designed and executed phase III studies are lacking. An important application of radiotherapy is palliation of tumor-related symptoms in the chest and in metastatic sites, such as bones and brain. In small cell lung cancer, routine applications of radiotherapy include chest radiotherapy in limited disease and prophylactic cranial irradiation in complete responders to chemotherapy, each increasing survival by about 5%.

Management of unresected stage III non-small cell lung cancer: a systematic review

PURPOSE

To conduct a systematic review to determine the most effective therapy for patients with unresected stage III non-small cell lung cancer.

METHODS

Relevant randomized trials and meta-analyses were identified through a systematic search of the literature.

RESULTS

Forty-seven trials and six meta-analyses were included. No statistically significant survival differences were detected for immediate versus delayed administration of radiotherapy or different doses of hyperfractionated radiotherapy. Three of 12 trials comparing various doses and schedules of radiotherapy detected a statistically significant survival advantage with higher radiation doses. All meta-analyses found a statistically significant survival advantage for chemoradiation, particularly platinum-based, compared with radiation alone. One meta-analysis and three trials comparing concurrent with sequential chemoradiation detected a statistically significant survival advantage with concurrent administration. Increased toxicities, especially esophagitis and hematologic events, were generally associated with concurrent chemoradiation. The survival advantage for concurrent platinum-based chemoradiation corresponds to a 4% absolute survival benefit at 2 years. With respect to trials comparing different chemotherapy regimens or schedules, there is insufficient evidence to determine which particular regimen or schedule is most effective.

CONCLUSION

Palliative radiotherapy can provide symptom relief for symptomatic patients with poor performance status. For patients with good performance status, chemoradiation improves survival compared with radiotherapy alone, particularly when the two modalities are administered concurrently. Sequential chemoradiation is a treatment option for borderline-status patients. Adequate assessment of performance status is important when evaluating treatment options for patients with unresected non-small cell lung cancer. Patients and physicians should have a full discussion of the benefits, limitations, and toxicities of therapy.

Combined-modality therapy with gemcitabine and radiotherapy as a bladder preservation strategy: results of a phase I trial

PURPOSE

We conducted a phase I trial of gemcitabine given twice weekly with concurrent radiotherapy in patients with muscle-invasive bladder cancer.

PATIENTS AND METHODS

Eligible patients underwent maximal transurethral resection of their bladder tumors followed by twice-weekly infusion of gemcitabine with 2 Gy/d concurrent radiotherapy to the bladder, for a total of 60 Gy over 6 weeks. The starting dose of gemcitabine was 10 mg/m(2) with subsequent dose levels of 20, 27, 30, and 33 mg/m(2). The primary end point was the determination of the maximum-tolerated dose (MTD) of twice weekly gemcitabine with concurrent radiotherapy. Secondary end points included assessment of toxicity associated with combined-modality therapy and initial assessment of the rate of bladder preservation.

RESULTS

Twenty-four patients were enrolled and 23 were assessable for toxicity and response. No significant toxicity was demonstrated at the 10 or 20 mg/m(2) twice-weekly doses. Dose-limiting toxicity (DLT) occurred in two of three patients treated at 33 mg/m(2). Intermediate dose levels of 27 and 30 mg/m(2) were then evaluated. The MTD of gemcitabine was 27 mg/m(2). The DLT was systemic, manifested as an elevation in liver function tests, malaise, and edema. Fifteen of 23 patients (65%) are alive with bladders intact and no evidence of recurrent disease at a median follow-up of 43 months.

CONCLUSION

Twice-weekly gemcitabine with concurrent radiotherapy at 2 Gy/d to a total dose of 60 Gy is well-tolerated. The MTD of gemcitabine is 27 mg/m(2). There is a high rate of bladder preservation in this selected group of patients.

A phase I/II trial of induction chemotherapy with carboplatin and gemcitabine followed by concurrent vinorelbine and paclitaxel with chest radiation in patients with stage III non-small cell lung cancer

PURPOSE

We designed a phase I/II trial in order to evaluate the efficacy and tolerability of induction carboplatin and gemcitabine and the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of subsequent chemoradiotherapy with weekly vinorelbine and paclitaxel in patients with stage III non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients had pathologically confirmed N2-N3 stage NSCLC, adequate end-organ function, and ECOG performance status 0-2. Carboplatin was administered at an AUC of 5 on day 1 and gemcitabine 1000 mg/m2 on days 1 and 8, every 21 days, for two cycles, followed by weekly vinorelbine 10-15 mg/m2 and paclitaxel 50 mg/m2 and conventional chest radiotherapy up to 66 Gy. Patients with resectable disease underwent thoracotomy after 40-45 Gy.

RESULTS

Thirty-nine eligible patients were enrolled; 17 had stage IIIB NSCLC. Grade 3 esophagitis developed in 4/5 patients on the second dose level of chemoradiotherapy (i.e. vinorelbine 15 mg/m2) and was considered dose-limiting. Of 34 patients treated at the maximum tolerated dose (i.e. vinorelbine 10 mg/m2), 2 patients (6%) had pneumonitis >grade 2 and 3 (9%), esophagitis >grade 2. Induction chemotherapy was well tolerated with only one patient developing >grade 2 non-hematologic toxicity (nausea). Forty-one percent of patients had an objective response after induction chemotherapy and 51% after chemoradiotherapy. Nineteen patients, 16 of whom had stage IIIA, underwent surgical resection. The pathologic complete response rate was 16% (42% in the mediastinal lymph nodes). With a median follow-up of 31 months, the 3-year progression-free survival (PFS) and overall survival (OS) rates were 23 and 34%, respectively, and the median OS was 25 months.

CONCLUSIONS

We identified a well-tolerated and active chemoradiotherapy regimen. Survival results are promising and the addition of a biologic agent to this regimen is of interest.

Neoadjuvant radiotherapy concurrent with weekly paclitaxel and carboplatin and followed by surgery in locally advanced non-small-cell lung cancer

Thirty-seven patients were enrolled in a phase II study to evaluate the efficacy and toxicity of neoadjuvant radiotherapy concurrent with weekly paclitaxel and carboplatin in locoregionally advanced non-small-cell lung cancer (NSCLC). The study was also designed to evaluate the operability following concurrent chemoirradiation. The following response rates to chemoirradiation were obtained: complete response (CR) 5 of 37 (13.5%), partial response 14 of 37 (38%), stable disease 12 of 37 (32.5%) and PD 6 of 37 (16%). Twenty patients underwent surgery, and in 19 patients the tumor was totally resected. There was pathologic CR in 4 patients. Moderate/severe esophagitis developed in 16 patients (43%); hematologic toxicity was mild. There was one case of postoperative mortality. Nine patients are alive without evidence of disease at 5+ to 39+ months. Median survival is 22 months. It is concluded that neoadjuvant radiotherapy concurrent with weekly paclitaxel/carboplatin is effective and well tolerated in patients and feasible for patients with locally advanced NSCLC, allowing complete tumor resection in 56% of the cases.

The mechanism of action of radiosensitization of conventional chemotherapeutic agents

It is not an exaggeration to state that most of the advances in curing cancer in the last decade have come from successful combinations of conventional chemotherapeutic agents with radiation therapy. Further improvements in therapy will depend on understanding the mechanisms by which chemotherapy improves the effectiveness of radiation in model systems and in patients. In this review, we discuss the mechanisms of action of the fluoropyrimidines, gemcitabine, and the platinums. The fluoropyrimidines (5-fluorouracil and fluorodeoxyuridine) increase the effectiveness of radiation chiefly when given before and during radiation. Increased radiation sensitivity occurs in cells that progress inappropriately into S phase in the presence of drug, suggesting a key role for dysregulation of S-phase checkpoints. Gemcitabine may radiosensitize by a similar mechanism, although the relative roles of specific DNA repair pathways (such as homologous end rejoining) and of apoptosis remain to be determined. For both of these categories of drugs, sensitization probably results when cells that are progressing inappropriately through S phase misrepair DNA damage inflicted by radiation. Thus, loss of the S-phase checkpoint in cancer cells may provide the molecular basis for selective killing of tumors compared with normal tissues. Cisplatin has multiple effects on cells, such as adduct formation and DNA damage repair inhibition, but the mechanism for selectivity against cancer cells compared with normal cells is not yet determined. The identification of the enzymatic targets for these drugs offers the potential to develop predictive assays for response and to develop methods of imaging the progress of therapy.

Comments on treatment strategy for locally advanced non-small cell lung cancer

In spite of significant improvement in local and in systemic treatment, long-term survival of patients with locally advanced non-small cell lung cancer (NSCLC) remains disappointing. The main reason may be our reluctance to explore the optimal ways of combining new modalities of irradiation with the new drugs. A survey of on-going clinical trials points to weak scientific collaboration between radiotherapists and medical oncologists. A comparison of different treatment strategies reveals that only the best local treatment combined with the best systemic treatment can lead to a clinically meaningful improvement in long-term survival. Curing a higher percentage of patients is the first step in our attempts to combat therapeutic nihilism.

Combined chemotherapy and radiotherapy in inoperable non-small cell lung cancer

Despite its low efficacy, radiotherapy has traditionally been considered the mainstay of treatment in inoperable stage III NSCLC. One of the attempts to improve the outcome is combining radiation with chemotherapy. This strategy is expected to increase the cure rate not only by improved locoregional tumor control but also by elimination of micrometastases outside the radiotherapy field. Chemotherapy and radiation may be applied in sequence or concurrently. The results of randomized studies testing these two strategies have been inconsistent, however a series of recent trials and the metaanalysis demonstrated a survival benefit of chemoradiation over radiotherapy alone. Recently, concurrent chemotherapy and radiation was found to be superior to sequential application but toxicity of the former is higher. The value of new agents (taxanes, vinorelbine, gemcitabine and topoisomerase inhibitors) in combined modality therapy of NSCLC seems to be promising, but warrants further clinical evaluation.

Chemoradiotherapy of non-small cell lung cancer

The efficacy of radiotherapy in locally advanced unresectable non-small cell lung cancer is low. This method does not provide effective eradication of bulky disease in the thorax, neither does it prevent uncontrolled systemic disease. The addition of chemotherapy to radiation results in increased cure rate by both improving tumor control in the thorax and by eliminating or delaying the emergence of metastatic disease. The two most frequently tested strategies of combining chemotherapy and radiation include primary chemotherapy followed by radiation and concurrent application of both methods. This review provides the rationale for this strategy and presents the results of major Phase III studies. Discussed are advantages of chemoradiation, its limitations in clinical practice and prospects for the future.

Combined modality treatment with chemotherapy and radiation in locally advanced non-small cell lung cancer

This article reviews combined chemotherapy and radiation in locally advanced inoperable non-small cell lung cancer. Presented are rationale for the use of this strategy, methods of combining drugs and radiation and results of major phase III trials.