Assessment of Toxic Effects and Survival in Treatment Deescalation With Radiotherapy vs Transoral Surgery for HPV-Associated Oropharyngeal Squamous Cell Carcinoma: The ORATOR2 Phase 2 Randomized Clinical Trial.

Importance: The optimal approach for treatment deescalation in human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCCs) is unknown. Objective: To assess a primary radiotherapy (RT) approach vs a primary transoral surgical (TOS) approach in treatment deescalation for HPV-related OPSCC. Design, Setting, and Participants: This international, multicenter, open-label parallel-group phase 2 randomized clinical trial was conducted at 9 tertiary academic cancer centers in Canada and Australia and enrolled patients with T1-T2N0-2 p16-positive OPSCC between February 13, 2018, and November 17, 2020. Patients had up to 3 years of follow-up. Interventions: Primary RT (consisting of 60 Gy of RT with concurrent weekly cisplatin in node-positive patients) vs TOS and neck dissection (ND) (with adjuvant reduced-dose RT depending on pathologic findings). Main Outcomes and Measures: The primary end point was overall survival (OS) compared with a historical control. Secondary end points included progression-free survival (PFS), quality of life, and toxic effects. Results: Overall, 61 patients were randomized (30 [49.2%] in the RT arm and 31 [50.8%] in the TOS and ND arm; median [IQR] age, 61.9 [57.2-67.9] years; 8 women [13.6%] and 51 men [86.4%]; 31 [50.8%] never smoked). The trial began in February 2018, and accrual was halted in November 2020 because of excessive toxic effects in the TOS and ND arm. Median follow-up was 17 months (IQR, 15-20 months). For the OS end point, there were 3 death events, all in the TOS and ND arm, including the 2 treatment-related deaths (0.7 and 4.3 months after randomization, respectively) and 1 of myocardial infarction at 8.5 months. There were 4 events for the PFS end point, also all in the TOS and ND arm, which included the 3 mortality events and 1 local recurrence. Thus, the OS and PFS data remained immature. Grade 2 to 5 toxic effects occurred in 20 patients (67%) in the RT arm and 22 (71%) in the TOS and ND arm. Mean (SD) MD Anderson Dysphagia Inventory scores at 1 year were similar between arms (85.7 [15.6] and 84.7 [14.5], respectively). Conclusions and Relevance: In this randomized clinical trial, TOS was associated with an unacceptable risk of grade 5 toxic effects, but patients in both trial arms achieved good swallowing outcomes at 1 year. Long-term follow-up is required to assess OS and PFS outcomes. Trial Registration: Clinicaltrials.gov Identifier: NCT03210103.

Randomized Trial of Radiotherapy Versus Transoral Robotic Surgery for Oropharyngeal Squamous Cell Carcinoma: Long-Term Results of the ORATOR Trial.

PURPOSE: The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has risen rapidly, because of an epidemic of human papillomavirus infection. The optimal management of early-stage OPSCC with surgery or radiation continues to be a clinical controversy. Long-term randomized data comparing these paradigms are lacking. METHODS: We randomly assigned patients with T1-T2, N0-2 (≤ 4 cm) OPSCC to radiotherapy (RT) (with chemotherapy if N1-2) versus transoral robotic surgery plus neck dissection (TORS + ND) (with or without adjuvant therapy). The primary end point was swallowing quality of life (QOL) at 1-year using the MD Anderson Dysphagia Inventory. Secondary end points included adverse events, other QOL outcomes, overall survival, and progression-free survival. All analyses were intention-to-treat. Herein, we present long-term outcomes from the trial. RESULTS: Sixty-eight patients were randomly assigned (n = 34 per arm) between August 10, 2012, and June 9, 2017. Median follow-up was 45 months. Longitudinal MD Anderson Dysphagia Inventory analyses demonstrated statistical superiority of RT arm over time (P = .049), although the differences beyond 1 year were of smaller magnitude than at the 1-year timepoint (year 2: 86.0 ± 13.5 in the RT arm v 84.8 ± 12.5 in the TORS + ND arm, P = .74; year 3: 88.9 ± 11.3 v 83.3 ± 13.9, P = .12). These differences did not meet the threshold to qualify as a clinically meaningful change at any timepoint. Certain differences in QOL concerns including more pain and dental concerns in the TORS + ND arm seen at 1 year resolved at 2 and 3 years; however, TORS patients started to use more nutritional supplements at 3 years (P = .015). Dry mouth scores were higher in RT patients over time (P = .041). CONCLUSION: On longitudinal analysis, the swallowing QOL difference between primary RT and TORS + ND approaches persists but decreases over time. Patients with OPSCC should be informed about the pros and cons of both treatment options (ClinicalTrials.gov identifier: NCT01590355).

Radiotherapy versus transoral robotic surgery and neck dissection for oropharyngeal squamous cell carcinoma (ORATOR): an open-label, phase 2, randomised trial.

BACKGROUND: Transoral robotic surgery (TORS) with concurrent neck dissection has supplanted radiotherapy in the USA as the most common treatment for oropharyngeal squamous cell carcinoma (OPSCC), yet no randomised trials have compared these modalities. We aimed to evaluate differences in quality of life (QOL) 1 year after treatment. METHODS: The ORATOR trial was an investigator-initiated, multicentre, international, open-label, parallel-group, phase 2, randomised study. Patients were enrolled at six hospitals in Canada and Australia. We randomly assigned (1:1) patients aged 18 years or older, with Eastern Cooperative Oncology Group scores of 0-2, and with T1-T2, N0-2 (≤4 cm) OPSCC tumour types to radiotherapy (70 Gy, with chemotherapy if N1-2) or TORS plus neck dissection (with or without adjuvant chemoradiotherapy, based on pathology). Following stratification by p16 status, patients were randomly assigned using a computer-generated randomisation list with permuted blocks of four. The primary endpoint was swallowing-related QOL at 1 year as established using the MD Anderson Dysphagia Inventory (MDADI) score, powered to detect a 10-point improvement (a clinically meaningful change) in the TORS plus neck dissection group. All analyses were done by intention to treat. This study is registered with ClinicalTrials.gov (NCT01590355) and is active, but not currently recruiting. FINDINGS: 68 patients were randomly assigned (34 per group) between Aug 10, 2012, and June 9, 2017. Median follow-up was 25 months (IQR 20-33) for the radiotherapy group and 29 months (23-43) for the TORS plus neck dissection group. MDADI total scores at 1 year were mean 86·9 (SD 11·4) in the radiotherapy group versus 80·1 (13·0) in the TORS plus neck dissection group (p=0·042). There were more cases of neutropenia (six [18%] of 34 patients vs none of 34), hearing loss (13 [38%] vs five [15%]), and tinnitus (12 [35%] vs two [6%]) reported in the radiotherapy group than in the TORS plus neck dissection group, and more cases of trismus in the TORS plus neck dissection group (nine [26%] vs one [3%]). The most common adverse events in the radiotherapy group were dysphagia (n=6), hearing loss (n=6), and mucositis (n=4), all grade 3, and in the TORS plus neck dissection group, dysphagia (n=9, all grade 3) and there was one death caused by bleeding after TORS. INTERPRETATION: Patients treated with radiotherapy showed superior swallowing-related QOL scores 1 year after treatment, although the difference did not represent a clinically meaningful change. Toxicity patterns differed between the groups. Patients with OPSCC should be informed about both treatment options. FUNDING: Canadian Cancer Society Research Institute Grant (#701842), Ontario Institute for Cancer Research Clinician-Scientist research grant, and the Wolfe Surgical Research Professorship in the Biology of Head and Neck Cancers grant.

Evaluating organ preservation outcome as treatment endpoint for T1aN0 glottic cancer.

OBJECTIVES/HYPOTHESIS: Common endpoints in reporting the outcomes for early glottic cancer do not highlight the importance of organ preservation. We evaluated the treatment outcomes among patients with T1aN0 laryngeal cancer with laryngectomy-free disease-specific survival (LFS-DSS), which is defined as time to total laryngectomy or time to death from cancer cause, against all other endpoints. STUDY DESIGN: Outcome research on an institutional database. METHODS: A retrospective review covered all consecutive patients from 2003 to 2013. Patients with T1a laryngeal squamous cell carcinoma (SCC) were offered the options of either radiation treatment (RT) or transoral laser microsurgery (TLM). Tumor control, survival outcomes, standard definition laryngectomy-free survival (LFS), and LFS-DSS were calculated. RESULTS: There were 105 patients, of whom 53 were treated with TLM and 52 were treated with RT. There were 11 recurrences within the TLM group, of which four were successfully salvaged with repeated TLM and two were salvaged with RT. Among the four recurrences within the RT group, all four patients had salvage total laryngectomies. The 5-year overall survival for patients treated with TLM versus RT was 86% versus 85% (P = .887), disease-free survival was 69% versus 78% (P = .151), LFS was 65% versus 77% (P = .198), LFS-DSS was 100% versus 88% (P = .030), and ultimate locoregional control was 100% in both groups. CONCLUSIONS: Patients with T1aN0 glottic SCC treated with RT or TLM have similar survival outcomes. Patients with T1a tumor treated with TLM have better organ preservation compared to RT, when measured with LFS-DSS. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:1322-1327, 2017.

Role of endolaryngeal surgery (with or without laser) versus radiotherapy in the management of early (T1) glottic cancer: a systematic review.

BACKGROUND: Treatment options for early glottic cancer include transoral microsurgery or radiotherapy (RT). There is continuing debate about which is the superior treatment. METHODS: The literature was searched from 1996 to 2011 using MEDLINE, EMBASE, and Cochrane Library. A quality assessment of each included study was conducted and reported. RESULTS: There is no evidence in favor of 1 treatment modality when considering likelihood of local control or overall survival. There is a suggestion that RT may be associated with less measureable perturbation of voice as compared to surgery, but no significant differences were seen in patient perception. The likelihood of laryngeal preservation may be higher when surgery can be offered as initial treatment. CONCLUSION: For patients with early (T1) glottic cancer, treatment options include the equally effective endolaryngeal surgery, with or without laser, or radiation therapy. The choice between treatment modalities should be based on patient and clinician preferences and general medical condition.

Does HPV type affect outcome in oropharyngeal cancer?

BACKGROUND: An epidemic of human papillomavirus (HPV)-related oropharyngeal squamous cell cancer (OPSCC) has been reported worldwide largely due to oral infection with HPV type-16, which is responsible for approximately 90% of HPV-positive cases. The purpose of this study was to determine the rate of HPV-positive oropharyngeal cancer in Southwestern Ontario, Canada. METHODS: A retrospective search identified ninety-five patients diagnosed with OPSCC. Pre-treatment biopsy specimens were tested for p16 expression using immunohistochemistry and for HPV-16, HPV-18 and other high-risk subtypes, including 31,33,35,39,45,51,52,56,58,59,67,68, by real-time qPCR. RESULTS: Fifty-nine tumours (62%) were positive for p16 expression and fifty (53%) were positive for known high-risk HPV types. Of the latter, 45 tumors (90%) were identified as HPV-16 positive, and five tumors (10%) were positive for other high-risk HPV types (HPV-18 (2), HPV-67 (2), HPV-33 (1)). HPV status by qPCR and p16 expression were extremely tightly correlated (p < 0.001, Fishers exact test). Patients with HPV-positive tumors had improved 3-year overall (OS) and disease-free survival (DFS) compared to patients with HPV-negative tumors (90% vs 65%, p = 0.001; and 85% vs 49%, p = 0.005; respectively). HPV-16 related OPSCC presented with cervical metastases more frequently than other high-risk HPV types (p = 0.005) and poorer disease-free survival was observed, although this was not statistically significant. CONCLUSION: HPV-16 infection is responsible for a significant proportion of OPSCC in Southwestern Ontario. Other high-risk subtypes are responsible for a smaller subset of OPSCC that present less frequently with cervical metastases and may have a different prognosis.

Early-stage squamous cell carcinoma of the oropharynx: radiotherapy vs. trans-oral robotic surgery (ORATOR)--study protocol for a randomized phase II trial.

BACKGROUND: The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has markedly increased over the last three decades due to newly found associations with human papillomavirus (HPV) infection. Primary radiotherapy (RT) is the treatment of choice for OPSCC at most centers, and over the last decade, the addition of concurrent chemotherapy has led to a significant improvement in survival, but at the cost of increased acute and late toxicity. Transoral robotic surgery (TORS) has emerged as a promising alternative treatment, with preliminary case series demonstrating encouraging oncologic, functional, and quality of life (QOL) outcomes. However, comparisons of TORS and RT in a non-randomized fashion are susceptible to bias. The goal of this randomized phase II study is to compare QOL, functional outcomes, toxicity profiles, and survival following primary RT (± chemotherapy) vs. TORS (± adjuvant [chemo] RT) in patients with OPSCC. METHODS/DESIGN: The target patient population comprises OPSCC patients who would be unlikely to require chemotherapy post-resection: Tumor stage T1-T2 with likely negative margins at surgery; Nodal stage N0-2, ≤3 cm in size, with no evidence of extranodal extension on imaging. Participants will be randomized in a 1:1 ratio between Arm 1 (RT ± chemotherapy) and Arm 2 (TORS ± adjuvant [chemo] RT). In Arm 1, patients with N0 disease will receive RT alone, whereas N1-2 patients will receive concurrent chemoradiation. In Arm 2, patients will undergo TORS along with selective neck dissections, which may be staged. Pathologic high-risk features will be used to determine the requirement for adjuvant radiotherapy +/- chemotherapy. The primary endpoint is QOL score using the M.D. Anderson Dysphagia Inventory (MDADI), with secondary endpoints including survival, toxicity, other QOL outcomes, and swallowing function. A sample of 68 patients is required. DISCUSSION: This study, if successful, will provide a much-needed randomized comparison of the conventional strategy of primary RT vs. the novel strategy of primary TORS. The trial is designed to provide a definitive QOL comparison between the two arms, and to inform the design of an eventual phase III trial for survival outcomes. TRIAL REGISTRATION: NCT01590355.

Ki-67 expression predicts radiotherapy failure in early glottic cancer.

BACKGROUND: Early-stage laryngeal squamous cell carcinoma is managed with radiotherapy or endoscopic surgery. Although cure rates are high, radiation failures often require total laryngectomy for salvage. Biomarkers that can predict tumour radioresistance may be useful in modifying the treatment approach for individual patients. METHODS: Retrospective patient chart review yielded 75 patients with T1-T2 glottic squamous cell carcinoma treated with radiation therapy at the London Health Sciences Centre. Pretreatment tumour biopsies were immunostained for B-cell lymphoma 2 (Bcl-2), Ki-67, and epidermal growth factor receptor (EGFR) to correlate biomarker expression with disease-free survival (DFS). RESULTS: Ki-67 expression was strongly associated with recurrence following radiation and independently predicted poor DFS (hazard ratio 4.86, 95% CI 1.58-15.00; p  =  .006). EGFR and Bcl-2 were not associated with a risk of recurrence. CONCLUSIONS: Ki-67 expression identified a subset of patients with increased risk of local recurrence after radiation therapy. Ki-67 expression can potentially guide improved personalized treatments for patients with early-stage glottic squamous cell carcinomas.

Adjuvant carboplatin and paclitaxel chemotherapy interposed with involved field radiation for advanced endometrial cancer.

OBJECTIVE: To evaluate recurrence and survival associated with adjuvant carboplatin and paclitaxel chemotherapy interposed with involved field radiation for advanced endometrial cancer. METHOD: This is a prospective cohort study of women with Stage III and IV endometrial cancer treated at a single institution between April 2002 and July 2006. Adjuvant therapy consisted of 4 cycles of intravenous paclitaxel (175 mg/m(2)) and carboplatin (350 mg/m(2)) every 3 weeks, followed by external beam radiotherapy (RT) to the pelvis (45 Gy), then another 2 cycles of chemotherapy. Para-aortic RT and/or HDR vault brachytherapy were added at the discretion of the treating physician. Toxicity of this protocol was previously reported. Primary endpoints for this study were disease-free and overall survival rates. RESULTS: Forty-three patients with a median age of 64 years (46-83 years) were evaluated. The majority had Stage IIIC disease (63%), and the most common histology was serous carcinoma (49%). Six cycles of combination chemotherapy were completed in 81%, and all patients completed pelvic RT. Median follow-up was 30 months (9-71 months). Twenty-one patients (49%) recurred at a median of 17 months (7-62 months). There were only 3 local recurrences, including 2 in the pelvis and 1 in the vagina/vulva. Median disease-free survival (DFS) was 50 months and median overall survival (OS) has not been reached. Three year DFS and OS rates were 53% and 68%, respectively. CONCLUSION: Adjuvant carboplatin and paclitaxel chemotherapy interposed with involved field radiation is associated with a low rate of local recurrence and favorable survival for advanced endometrial cancer.

Optimization of high-dose-rate cervix brachytherapy applicator placement: the benefits of intraoperative ultrasound guidance.

PURPOSE: To promote efficient workflow for image-guided high-dose-rate (HDR) brachytherapy (BT) for cervix cancer by implementing intraoperative ultrasound (US) guidance for placement and optimization of intrauterine applicators. We sought to establish this as part of routine radiation oncology practice without radiology consultation. METHODS AND MATERIALS: Thirty-five consecutive insertions were performed in 21 women between July 2006 and March 2007. Cervical dilation, tandem selection and insertion were guided by transabdominal US. Final tandem position following vaginal applicator insertion was also confirmed by US. Computed tomography (CT) imaging was used for treatment planning and to assess perforation and applicator suitability for each patient anatomy. RESULTS: Intrauterine tandem insertion was successfully guided by US in the majority of procedures (34/35). CT imaging confirmed accurate placement within the uterine canal in each case, compared with a historic institutional perforation rate of 10%. Visualizing patient anatomy during insertion altered the selection of tandem length and angle in 49% of cases, resulting in improved applicator matching to anatomy. Average insertion time significantly decreased from 34 to 26 minutes (p=0.01). Requests for assistance from gynecologic surgical oncology declined from 38% to 5.7% of procedures. CONCLUSIONS: Intraoperative US guidance for cervix BT has been successfully implemented with staff and equipment from radiation oncology. Using US during every insertion has led to improved applicator selection and placement while decreasing procedure time and reducing out of department consultations. These changes have eliminated repeat insertions due to unfavorable applicator placement (as revealed on postoperative CT), thus improving department efficiency and quality of patient care.

Compromised local control due to treatment interruptions and late treatment breaks in early glottic cancer: Population-based outcomes study supporting need for intensified treatment schedules.

PURPOSE: This population-based study describes the treatment of early glottic cancer in Ontario, Canada and assesses whether treatment variations were associated with treatment effectiveness. METHODS AND MATERIALS: We studied 491 T1N0 and 213 T2N0 patients. Data abstracted from charts included age, sex, stage, treatment details, disease control, and survival. RESULTS: The total dose ranged from 50 to 70 Gy, and the daily dose ranged from 1.9 to 2.8 Gy. In 90%, treatment duration was between 25 and 50 days. Field sizes, field reductions, beam arrangement, and beam energy varied. Late treatment breaks occurred in 13.6% of T1N0 and 27.1% of T2N0 cases. Local control was comparable to other reports for T1N0 (82% at 5 years), but was only 63.2% in T2N0. Variables associated with local failure in T1N0 were age less than 49 years (relative risk [RR], 3.21; 95% confidence interval [CI], 1.49-6.90) and >3 treatment interruption days (RR, 2.43; 95% CI, 1.00-5.91). In T2N0, these were field reduction (RR, 2.33; 95% CI, 1.23-4.42) and late treatment breaks (RR, 2.19; 95% CI, 1.09-4.41). CONCLUSION: Some aspects of treatment for early glottic cancer were associated with worse local control. Problems with protracted treatment are of particular concern, underscoring the need for randomized studies to intensify radiotherapy.

Brain metastases from endometrial carcinoma: a retrospective study.

OBJECTIVE: The objective of this study was to examine the characteristics and treatment results of patients at our center with brain metastases from endometrial carcinoma. METHODS: Between January 1991 and March 2003, there were 1295 women referred to the London Regional Cancer Centre with the diagnosis of endometrial cancer, and eight of these women (0.6%) developed brain metastases. The medical records of these eight women were reviewed to assess patient and tumor characteristics at primary diagnosis. Treatment and clinical outcomes were analyzed. RESULTS: The majority of patients had poor prognostic factors associated with the primary tumor, including high grade and advanced stage. The median age at diagnosis of brain metastases was 66 years. The median interval between completion of primary tumor treatment and diagnosis of brain metastases was 2 months. Three patients had no other evidence of systemic disease, while five had disseminated disease. Four patients had a single brain metastasis, while four had multiple lesions. Seven patients received whole brain radiation therapy in addition to systemic steroids, of which six had temporary improvement or resolution in symptoms. Median survival following diagnosis of brain metastases was 3.5 months. CONCLUSIONS: Brain metastases from endometrial cancer are uncommon. Associated factors include high grade and advanced stage. The majority of women in this series presented with brain metastases shortly after completion of primary treatment for their endometrial cancer. The prognosis following brain metastases is generally very poor. Innovative treatment strategies are needed to improve the outcome of these patients.

Management and outcome differences in supraglottic cancer between Ontario, Canada, and the Surveillance, Epidemiology, and End Results areas of the United States.

PURPOSE: We compared the management and outcome of supraglottic cancer in Ontario, Canada, with that in the Surveillance, Epidemiology, and End Results (SEER) Program areas in the United States. METHODS: Electronic, clinical, and hospital data were linked to cancer registry data and supplemented by chart review where necessary. Stage-stratified analyses compared initial treatment and survival in the SEER areas (n = 1,643) with a random sample from Ontario (n = 265). We also compared laryngectomy rates at 3 years in those patients 65 years and older at diagnosis. RESULTS: Radical surgery was more commonly used in SEER, with absolute differences increasing with increasing stage: I/II, 17%; III, 36%; and IV, 45%. The 5-year survival rates were 74% in Ontario and 56% in SEER for stage I/II disease (P =.01), 55.7% in Ontario and 46.8% in SEER for stage III disease (P =.40), and 28.5% in Ontario and 29.1% in SEER for stage IV disease (P =.28). Cancer-specific survival results mirrored the overall survival results with the exception of stage IV disease, for which 34.6% of Ontario patients survived their cancer compared with 38.1% in SEER (P =.10). This stage IV difference was more pronounced when we further controlled for possible cause of death errors by restricting the comparison to patients with a single primary cancer (P =.01). Three-year actuarial laryngectomy rates differed. In stage I/II, these rates were 3% in Ontario compared with 35% in SEER (P < 10(-3)). In stage III disease, the rates were 30% and 54%, respectively (P =.03), and in stage IV disease they were 33% and 64% (P =.002). CONCLUSION: There are large differences in the management of supraglottic cancer between the SEER areas of the United States and Ontario. Long-term larynx retention was higher in Ontario, where radiotherapy is widely regarded as the treatment of choice and surgery is reserved for salvage. In stages I to III, survival was similar in the two regions despite the differences in treatment policy. In stage IV, there may be a small survival advantage in the U.S. SEER areas related to the higher use of primary surgery.

A comparison of published head and neck stage groupings in laryngeal cancer using data from two countries.

The combination of T, N, and M classifications into stage groupings is meant to facilitate a number of activities including: the estimation of prognosis and the comparison of therapeutic interventions among similar groups of cases. We tested the UICC/AJCC fifth edition stage grouping and six other TNM-based groupings proposed for head and neck cancer for their ability to meet these expectations in laryngeal cancer using data from Ontario, Canada, and the area of Southern Norway surrounding Oslo. We defined four criteria to assess each grouping scheme: (1) the subgroups defined by T, N, and M comprising a given group within a grouping scheme have similar survival rates (hazard consistency); (2) the survival rates differ among the groups (hazard discrimination); (3) the prediction of cure is high (outcome prediction); and (4) the distribution of patients among the groups is balanced. We previously identified or derived a measure for each criterion, and the findings were summarized using a scoring system. The range of scores was from 0 (best) to 7 (worst). The data sets were population-based, with 861 cases from Ontario and 642 cases from Southern Norway. Clinical stage assignment was used and the outcome of interest was cause-specific survival. Summary scores across the seven schemes had similar ranges: 0.9 to 5.1 in Ontario and 1.8 to 5.7 in Southern Norway, but the ranking varied. Summing the scores across the two datasets, the TANIS-7 scheme (Head & Neck 1993;15:497-503) ranked first, and was ranked high in both datasets (first and second, respectively). The UICC/AJCC scheme ranked sixth out of seven schemes, and its ranking was fifth and seventh, respectively. UICC/AJCC stage groupings were defined without empirical investigation. When tested, this scheme did not perform best. Our results suggest that the usefulness of the TNM system could be enhanced by optimizing the design of stage groupings through empirical investigation.