Examining prognostic factors and patterns of failure in nasopharyngeal carcinoma following concomitant radiotherapy and chemotherapy: impact on future clinical trials

PURPOSE

Concomitant chemotherapy and radiotherapy (CCRT), followed by adjuvant chemotherapy, has improved the outcome of nasopharyngeal carcinoma (NPC). However, the prognosis and patterns of failure after this combined-modality treatment are not yet clear. In this report, the prognostic factors and failure patterns we observed with CCRT may shed new light in the design of future trials.

METHODS AND PATIENTS

One hundred forty-nine (149) patients with newly diagnosed and histologically proven NPC were prospectively treated with CCRT followed by adjuvant chemotherapy between April 1990 and December 1997. One hundred and thirty-three (89.3%) patients had MRI of head and neck for primary evaluation before treatment. Radiotherapy was delivered either at 2 Gy per fraction per day up to 70 Gy or 1.2 Gy per fraction, 2 fractions per day, up to 74.4 Gy. Chemotherapy consisted of cisplatin and 5-fluorouracil. According to the AJCC 1997 staging system, 32 patients were in Stage II, 53 in Stage III, and 64 in Stage IV (M0).

RESULTS

Univariate analysis revealed that WHO (World Health Organization) Type II histology, T4 classification, and parapharyngeal extension were poor prognostic factors for locoregional control. Multivariate analysis revealed that T4 disease was the most important adverse factor that affects locoregional control, the risk ratio being 5.965 (p = 0.02). Univariate analysis for distant metastasis revealed that T4 and N3 classifications, serum LDH level > 410 U/L (normal range, 180-460), parapharyngeal extension, and infiltration of the clivus were significantly associated with poor prognosis. Multivariate analysis, however, revealed that T4 classification and N3 category were the only two factors that predicted distant metastasis; the risk ratios were 3.994 (p = 0.02) and 3.390 (p = 0.01), respectively. Therefore, based on the risk factor analysis, we were able to identify low-, intermediate-, and high-risk patients. Low-risk patients were those without the risk factors mentioned above. They consisted of Stage II patients with T2aN0, T1N1, and T2aN1 categories and of Stage III patients with T1N2 and T2aN2 categories. Their risk of recurrence is low (4%). Intermediate-risk patients were those with at least one univariate risk factor. They are Stage II patients with T2bN0 and T2bN1 categories and Stage III patients with T2bN2 and T3N0-2 categories. The risk of recurrence is modest (18%). High-risk patients have risk factors by multivariate analysis. They are stage T4 or N3 patients. Their risk of recurrence is high (36%).

CONCLUSION

Low-risk patients have an excellent outcome. Future trials should focus on reducing treatment-associated toxicities and complications and reevaluate the benefit of sequential adjuvant chemotherapy. The recurrence in treatment of intermediate-risk patients is modest; CCRT and adjuvant chemotherapy may be the best standard for them. Patients with T4 and N3 disease have poorer prognosis. Hyperfractionated radiotherapy may be considered for the T4 patients. Future study in these high-risk patients should also address the problem of distant spread of the disease.

Long-term survival of nasopharyngeal carcinoma following concomitant radiotherapy and chemotherapy

PURPOSE

The purpose of this study is to demonstrate long-term survival of nasopharyngeal carcinoma treated with concomitant chemotherapy and radiotherapy (CCRT) followed by adjuvant chemotherapy.

METHODS AND PATIENTS

One hundred and seven patients with Stage III and IV (American Joint Committee on Cancer, AJCC, 1988) nasopharyngeal carcinoma (NPC) were treated with concomitant chemotherapy and radiotherapy (CCRT) followed by adjuvant chemotherapy between April 1990 and December 1997 in Koo Foundation Sun Yat-Sen Cancer Center, Taipei. The dose of radiation was 70 Gray (Gy) given in 35 fractions, 5 fractions per week. Two courses of chemotherapy, consisting of cisplatin and 5-fluorouracil, were delivered simultaneously with radiotherapy in Weeks 1 and 6 and two additional monthly courses were given after radiotherapy. According to the AJCC 1997 staging system, 32 patients had Stage II disease, 44 had Stage III, and 31 had Stage IV disease.

RESULTS

With median follow-up of 44 months, the 5-year overall survival rate in all 107 patients was 84.1%, disease-free survival rate was 74.4%, and locoregional control rate was 89.8%. The 3-year overall survival for Stage II was 100%, for Stage III it was 92.8%, and for Stage IV, 69. 4% (p = 0.0002). The 3-year disease-free survival for Stage II was 96.9%, for Stage III it was 87.7%, and for Stage IV it was 51.9% (p = 0.0001).

CONCLUSION

CCRT and adjuvant chemotherapy is effective in Taiwanese patients with advanced NPC. The prognosis of AJCC 1997 Stage II and III disease is excellent, but, for Stage IV (M0), it is relatively poor. Future strategies of therapy should focus on high-risk AJCC 1997 Stage IV (M0) cohort.

Concomitant radiotherapy and chemotherapy for early-stage nasopharyngeal carcinoma

PURPOSE

Early-stage nasopharyngeal carcinoma (NPC) continues to carry a failure rate of 15% to 30% when treated with radiotherapy alone; the benefit of concomitant radiotherapy and chemotherapy (CCRT) in early-stage NPC is unclear. The purpose of this report is to describe our efforts to improve treatment outcome in early-stage NPC after CCRT.

PATIENTS AND METHODS

Of 189 newly diagnosed NPC patients without evidence of distant metastases who were treated in our institution between 1990 and 1997, 44 presented with early-stage (stage I and II) disease according to the American Joint Committee on Cancer (AJCC) 1997 NPC staging system. Twelve of these patients were treated with radiotherapy alone and 32 with CCRT. Each patient's head and neck area was evaluated by magnetic resonance imaging or computed tomography. Radiotherapy was administered at 2 Gy per fraction per day, Monday through Friday, for 35 fractions for a total dose of 70 Gy. Chemotherapy consisting of cis-diamine-dichloroplatinum and fluorouracil was delivered simultaneously with radiotherapy in weeks 1 and 6 and sequentially for two monthly cycles after radiotherapy.

RESULTS

Patients who were treated with radiotherapy alone primarily had stage I disease, whereas none of those who were treated with CCRT had stage I disease (11 of 12 patients v none of 32 patients; P =.001). The locoregional control rate at 3 years for the radiotherapy group was 91.7% (median follow-up period, 34 months) and was 100% for the CCRT group (median follow-up period, 44 months) (P =.10). The 3-year disease-free survival rate in the radiotherapy group was 91.7% and was 96.9% in the CCRT group (P =.66).

CONCLUSION

Our results reveal excellent prognosis of AJCC 1997 stage II NPC treated with CCRT. Stage II patients with a greater tumor burden treated with CCRT showed an equal disease-free survival, compared with stage I patients treated with radiotherapy alone. A prospective randomized trial is underway to confirm the role of CCRT in stage II NPC.

Prognostic features and treatment outcome in locoregionally advanced nasopharyngeal carcinoma following concurrent chemotherapy and radiotherapy

PURPOSE

Concurrent chemotherapy and radiotherapy (CCRT) are effective in treatment of locoregionally advanced nasopharyngeal carcinoma (NPC). However, the prognostic factors after CCRT have not been evaluated. We therefore attempt to evaluate factors that influence treatment outcomes following CCRT.

METHODS AND MATERIALS

Seventy-four (5 in stage III and 69 in stage IV) patients with locoregionally advanced NPC were treated with CCRT. Radiotherapy was delivered either at 2 Gray (Gy) per fraction per day up to 70 Gy or 1.2 Gy, 2 fractions per day, up to 74.4 Gy. Concurrent chemotherapy consisted of cisplatin and 5-fluorouracil. Cox proportional-hazards model was used to analyze the prognostic factors which included age, gender, pathologic type, T, N, lactate dehydrogenase (LDH), and infiltration of the clivus.

RESULTS

The primary tumor control rate at 3 years was 96.7% (95% confidence interval [CI]: 92.5-100), distant metastasis-free survival 81.1% (95% CI: 70.6-91.6), disease-free survival 77.0% (95% CI: 65.3-88.7), and overall survival 79.8% (95% CI: 69.2-90.4) with a median follow-up interval of 29 months (range 15-74 months). Cox proportional-hazards model revealed that infiltration of the clivus and serum level of LDH before treatment were the most two important factors that predict distant metastases. Infiltration of the clivus and the serum LDH level greater than 410 U/L were strongly associated with distant metastasis-free survival (p = 0.0004 and p = 0.0002, respectively). When these two risk factors were considered together, no distant metastasis was observed in 40 patients with both intact clivus and LDH < or = 410 U/L. On the contrary, 13 of the remaining 34 patients with at least one risk factor developed distant metastasis (p = 0.0001).

CONCLUSION

Our study demonstrates that CCRT can improve the primary tumor control of 96.7% and disease-free survival of 77.0% at 3-year follow-up. Distant metastasis, however, is the major cause of failure. Infiltration of the clivus by the tumor and LDH greater than 410 U/L are the two independent and useful prognostic factors in patients with locoregionally advanced NPC who were treated with CCRT. Good- and poor-risk patients can be distinguished by virtue of their having both conditions.

Preoperative treatment of patients with locally advanced unresectable rectal adenocarcinoma utilizing continuous chronobiologically shaped 5-fluorouracil infusion and radiation therapy

BACKGROUND

This study was designed to determine the efficacy and maximally tolerated dose of 5-fluorouracil when administered by chronobiologically shaped prolonged infusion in combination with radiation therapy in patients with both locally advanced and unresectable rectal carcinoma.

METHODS

Eighteen sequential patients determined clinically to have either locally advanced or unresectable rectal carcinoma were treated by 4500 centigray (cGy) or 5580 cGy, respectively, combined with continuous chronobiologically modulated 5-FU infusion starting at 250 mg/m2/day, with the dose escalating in each cohort of 5 patients if no Grade 3 or higher toxicity was observed in each cohort. Imaging studies were obtained prior to and after completion of treatment.

RESULTS

All 18 patients completed the full course of radiation therapy and all were subsequently resectable for potential cure. The maximum tolerated dose of 5-FU was 275/m2/day for 5 weeks. Seven patients had a sphincter-sparing procedure, and ten patients underwent an abdominoperineal resection, all with clear margins. Five complete pathologic responses (28%) were obtained. The average follow-up time was 12 months with a range of 6 to 37 months. With the exception of two patients, one of whom declined surgery and one of whom died of widespread disease, all of the patients have remained free of disease.

CONCLUSIONS

The combination of radiation therapy and continuous chronobiologically shaped 5-FU infusion at a dose of up to 275/m2/day is well tolerated and appears to be more effective in downsizing and possibly downstaging locally advanced and unresectable rectal carcinoma than radiation therapy alone. Longer follow-up will determine whether ultimate disease free and overall survival are improved by this method.

Preoperative treatment of patients with locally advanced unresectable rectal adenocarcinoma utilizing continuous chronobiologically shaped 5-fluorouracil infusion and radiation therapy

BACKGROUND

This study was designed to determine the efficacy and maximally tolerated dose of 5-fluorouracil when administered by chronobiologically shaped prolonged infusion in combination with radiation therapy in patients with both locally advanced and unresectable rectal carcinoma.

METHODS

Eighteen sequential patients determined clinically to have either locally advanced or unresectable rectal carcinoma were treated by 4500 centigray (cGy) or 5580 cGy, respectively, combined with continuous chronobiologically modulated 5-FU infusion starting at 250 mg/m2/day, with the dose escalating in each cohort of 5 patients if no Grade 3 or higher toxicity was observed in each cohort. Imaging studies were obtained prior to and after completion of treatment.

RESULTS

All 18 patients completed the full course of radiation therapy and all were subsequently resectable for potential cure. The maximum tolerated dose of 5-FU was 275/m2/day for 5 weeks. Seven patients had a sphincter-sparing procedure, and ten patients underwent an abdominoperineal resection, all with clear margins. Five complete pathologic responses (28%) were obtained. The average follow-up time was 12 months with a range of 6 to 37 months. With the exception of two patients, one of whom declined surgery and one of whom died of widespread disease, all of the patients have remained free of disease.

CONCLUSIONS

The combination of radiation therapy and continuous chronobiologically shaped 5-FU infusion at a dose of up to 275/m2/day is well tolerated and appears to be more effective in downsizing and possibly downstaging locally advanced and unresectable rectal carcinoma than radiation therapy alone. Longer follow-up will determine whether ultimate disease free and overall survival are improved by this method.

Placental metastasis from primary ocular melanoma: a case report

Ocular malignant melanoma, similar to the cutaneous variety, may metastasize to the placenta, almost always in the presence of widespread disease. The prognosis is poor, and there is a 25% risk of spread to the fetus. All women with a history of this disease should be informed of the risks when they are contemplating pregnancy.

Arterial therapy of hepatic colorectal metastases

Considerable experience of the treatment of irresectable hepatic colorectal metastases has accumulated over the past three decades. In this review, the rationale for hepatic artery treatment of colorectal metastases to the liver is presented and various access techniques and chemotherapeutic agents for infusion are discussed. Randomized trials of hepatic artery chemotherapy (HAC) are analysed, and the promising results of recent studies combining less toxic and more effective agents are summarized. Continuous infusion pumps provide the most reliable and long-lasting access for HAC. Appropriate surgical techniques and medical management can minimize complications. Although tumour progression is best controlled by HAC, a clear-cut survival advantage has yet to be demonstrated. While hepatic artery infusion chemotherapy cannot yet be recommended outside investigational protocols, the experience gained so far should stimulate further studies.

The 2 A crystal structure of subtilisin E with PMSF inhibitor

Using enzyme prepared by the DNA recombination technique, subtilisin E from Bacillus subtilis was crystallized in space group P2(1)2(1)2(1) with two molecules in an asymmetric unit. The crystal structure of PMSF-inhibited subtilisin E was solved by molecular replacement followed by refinement with the X-PLOR program. This resulted in the 2.0 A structure of subtilisin E with an R-factor of 0.191 for 8-2 A data and r.m.s. deviations from ideal values of 0.021 A and 2.294 for bond lengths and bond angles respectively. The PMSF group covalently bound to Ser221 appeared very clearly in the electron density map. Except for the active site disturbed by PMSF binding, the structural features of subtilisin E are almost the same as in other subtilisins. The calcium-binding sites are different in detail in the two independent molecules of subtilisin E. Based on the structure, the remarkably enhanced heat stability of mutant N118S of subtilisin E is discussed. It is very likely that there is an additional water molecule in the mutant structure, which is hydrogen bonded to side chains of Ser118 and its neighbouring residues Lys27 and Asp120.

The SV40 small t intron is accurately and efficiently spliced in tobacco cells

We have introduced the SV40 small t intron into tobacco cells as part of a cauliflower mosaic virus 35S promoter-chloramphenicol acetyltransferase-SV40 transcription unit. We find that the small t intron is efficiently and accurately spliced in transgenic tobacco cells that carry this transcription unit. Our results indicate that there is substantial conservation of RNA processing signals between plants and animals, more than has been previously assumed. They also suggest that pre-mRNA processing in plants requires multiple branch sites for efficient processing.

Assessment of a method for immunochemical detection of antigen on nitrocellulose membranes

Immunoblotting techniques are widely used for detection of antigen immobilized on nitrocellulose membranes. There are many immunolabeling methods and staining methods available to disclose the presence of antigen in such techniques. Five common staining methods each for alkaline phosphatase and horseradish peroxidase were examined. The staining methods with the highest sensitivity and the lowest background were selected for studies comparing five immunological labeling methods using human IgG as a model antigen. Results were evaluated on the basis of the least amount of detectable antigen and background staining. The most sensitive dot-blot method was then tested for its applicability to Western blots. For both dot-blots and Western blots, the immunoalkaline phosphatase methods are more sensitive than the corresponding immunoperoxidase methods. The use of biotinylated secondary antibodies and an avidin-enzyme conjugate is recommended. Disclosure of alkaline phosphate is best achieved with naphthol AS phosphate as substrate and fast blue BB as chromogen. Peroxidase is best stained using H2O2 and diaminobenzidine (DAB). Potential endogenous enzyme activities are demonstrable by blotting methods but can be inhibited by including levamisole in the disclosure reaction medium for calf intestinal alkaline phosphatase indicators, or by incubation of blots with sodium azide and hydrogen peroxide before immunolabeling when using horseradish peroxidase indicators.

Plant cells do not properly recognize animal gene polyadenylation signals

We have introduced chimeric genes containing polyadenylation signals from a human gene and two animal virus genes into tobacco cells. We see, in all three cases, inefficient and 'aberrant' utilization of the foreign polyadenylation signals. We find that a chimeric gene carrying the polyadenylation site of the human growth hormone gene is polyadenylated at three sites in the vicinity of the site that is polyadenylated in human cells. A chimeric gene containing the polyadenylation site from the adenovirus 5 E1A gene is polyadenylated at a site 11 bases downstream from that reported in animal cells. A gene carrying the polyadenylation site from the SV40 early region is polyadenylated some 80 bases upstream from the site that is polyadenylated in animal cells. In all three cases, related mRNAs ending at flanking 'authentic' plant polyadenylation sites can be detected, indicating that the foreign polyadenylation signals are inefficiently utilized in tobacco cells.