Impact of compliance to chemoradiation on long-term outcomes in squamous cell carcinoma of the anus: results of a post hoc analysis from the randomised phase III ACT II trial.

BACKGROUND: Concurrent chemoradiation is standard-of-care for patients with squamous cell carcinoma of the anus. Poor compliance to chemotherapy, radiotherapy treatment interruptions and unplanned breaks may impact adversely on long-term outcomes. METHODS: The ACT II trial recruited 940 patients with localised squamous cell carcinoma of the anus, and assigned patients to mitomycin (week 1) or cisplatin (weeks 1 and 5), with fluorouracil (weeks 1 and 5) and radiotherapy (50.4 Gy in 28 fractions over 38 days). This post hoc analysis examined the association between baseline factors (age, gender, site, T stage and N stage), and compliance to treatment (radiotherapy and chemotherapy), and their effects on locoregional failure-free survival, progression-free survival (PFS) and overall survival (OS). Compliance was categorised into groups. Radiotherapy: six groups according to total dose and overall treatment time (OTT). Chemotherapy: three groups (A = per-protocol; B = dose reduction or delay; C = omitted). RESULTS: A total of 931/940 patients were assessable for radiotherapy and 936 for chemotherapy compliance. Baseline glomerular filtration rate <60 ml/min and cisplatin were significantly associated with poor week 5 compliance to chemotherapy (P = 0.003 and 0.02, respectively). Omission of week 5 chemotherapy was associated with significantly worse locoregional failure-free survival [hazard ratio (HR) 2.53 (1.33-4.82) P = 0.005]. Dose reductions/delays or omission of week 5 chemotherapy were associated with significantly worse PFS {HR: 1.56 [95% confidence interval (CI): 1.18-2.06], P = 0.002 and HR: 2.39 (95% CI: 1.44-3.98), P = 0.001, respectively} and OS [HR: 1.92 (95% CI: 1.41-2.63), P < 0.001 and HR: 2.88 (95% CI: 1.63-5.08), P < 0.001, respectively]. Receiving the target radiotherapy dose in >42 days is associated with worse PFS and OS [HR: 1.72 (95% CI: 1.17-2.54), P =0.006]. CONCLUSION: Poor compliance to chemotherapy and radiotherapy were associated with worse locoregional failure-free survival, PFS and OS. Treatment interruptions should be minimised, and OTT and total dose maintained. CLINICAL TRIAL NUMBER: ISRCTN 26715889.

Prediction of outcome in anal squamous cell carcinoma using radiomic feature analysis of pre-treatment FDG PET-CT.

PURPOSE: Incidence of anal squamous cell carcinoma (ASCC) is increasing, with curative chemoradiotherapy (CRT) as the primary treatment of non-metastatic disease. A significant proportion of patients have locoregional treatment failure (LRF), but distant relapse is uncommon. Accurate prognostication of progression-free survival (PFS) would help personalisation of CRT regimens. The study aim was to evaluate novel imaging pre-treatment features, to prognosticate for PFS in ASCC. METHODS: Consecutive patients with ASCC treated with curative intent at a large tertiary referral centre who underwent pre-treatment FDG-PET/CT were included. Radiomic feature extraction was performed using LIFEx software on baseline FDG-PET/CT. Outcome data (PFS) was collated from electronic patient records. Elastic net regularisation and feature selection were used for logistic regression model generation on a randomly selected training cohort and applied to a validation cohort using TRIPOD guidelines. ROC-AUC analysis was used to compare performance of a regression model encompassing standard clinical prognostic factors (age, sex, tumour and nodal stage-model A), a radiomic feature model (model B) and a combined radiomic/clinical model (model C). RESULTS: A total of 189 patients were included in the study, with 145 in the training cohort and 44 in the validation cohort. Median follow-up was 35.1 and 37. 9 months, respectively for each cohort, with 70.3% and 68.2% reaching this time-point with PFS. GLCM entropy (a measure of randomness of distribution of co-occurring pixel grey-levels), NGLDM busyness (a measure of spatial frequency of changes in intensity between nearby voxels of different grey-level), minimum CT value (lowest HU within the lesion) and SMTV (a standardized version of MTV) were selected for inclusion in the prognostic model, alongside tumour and nodal stage. AUCs for performance of model A (clinical), B (radiomic) and C (radiomic/clinical) were 0.6355, 0.7403, 0.7412 in the training cohort and 0.6024, 0.6595, 0.7381 in the validation cohort. CONCLUSION: Radiomic features extracted from pre-treatment FDG-PET/CT in patients with ASCC may provide better PFS prognosis than conventional staging parameters. With external validation, this might be useful to help personalise CRT regimens in the future.

Current concepts in imaging for local staging of advanced rectal cancer.

Imaging of rectal cancer has an increasingly pivotal role in the diagnosis, staging, and treatment stratification of patients with the disease. This is particularly true for advanced rectal cancers where magnetic resonance imaging (MRI) findings provide essential information that can change treatment. In this review we describe the rationale for the current imaging standards in advanced rectal cancer for both morphological and functional imaging on the baseline staging and reassessment studies. In addition the clinical implications and future methods by which radiologists may improve these are outlined relative to TNM8.

Session 1: The evolution and development of the multidisciplinary team approach: USA, European and UK experiences - what can we do better?

The process of determining the best treatments that should be offered to patients with newly diagnosed colon and rectal cancer remains highly variable around the world. The aim of this expert review was to agree the key elements of good quality preoperative treatment decision making.

Multicentre study of short-course radiotherapy and transanal endoscopic microsurgery for early rectal cancer.

BACKGROUND: Organ-preserving treatment for early-stage rectal cancer may avoid the substantial perioperative morbidity and functional sequelae associated with total mesorectal excision (TME). The initial results of an organ-preserving approach using preoperative short-course radiotherapy (SCRT) and transanal endoscopic microsurgery (TEMS) are presented. METHODS: Patients with cT1-2N0 rectal cancers staged using high-quality MRI and endorectal ultrasonography received SCRT, with TEMS 8-10 weeks later, at four regional referral centres between 2007 and 2013. Patients were generally considered high risk for TME surgery (a small number refused TME). RESULTS: Following SCRT and TEMS, 60 (97 per cent) of 62 patients had an R0 resection. Histopathological staging identified 20 ypT0 tumours, 23 ypT1, 18 ypT2 and one ypT3. Preoperative uT category was significantly associated with a complete pathological response, which was achieved in 13 of 27 patients with uT0/uT1 disease and in five of 29 with uT2 (P = 0·010). Acute complications affected 19 patients, the majority following TEMS. No fistulas occurred and no stomas were formed. Surveillance detected four intraluminal local recurrences at a median follow-up of 13 months, all in patients with tumours staged as ypT2. Salvage TME achieved R0 resection in three patients and a stent was placed in one patient owing to co-morbidities. CONCLUSION: SCRT with TEMS was effective in the majority of patients considered high risk for (or who refused) TME surgery.

Chronicle: results of a randomised phase III trial in locally advanced rectal cancer after neoadjuvant chemoradiation randomising postoperative adjuvant capecitabine plus oxaliplatin (XELOX) versus control.

BACKGROUND: In stage III colon cancer, oxaliplatin/5-fluorouracil (5-FU)-based adjuvant chemotherapy (FOLFOX) improves disease-free survival (DFS) and overall survival (OS). In rectal adenocarcinoma following neoadjuvant chemoradiation (CRT), we examined the benefit of postoperative adjuvant capecitabine and oxaliplatin (XELOX) chemotherapy. METHODS: Eligible patients were randomly assigned following fluoropyrimidine-based CRT and curative resection to observation or six cycles of XELOX. The primary end point was DFS; secondary end points were acute toxicity and OS. 390 patients were required in each arm, to detect an improvement in 3-year DFS from 40% to 50.5%, with 85% power and two-sided 5% significance level. RESULTS: The study closed prematurely in 2008 because of poor accrual. Only 113 patients were randomly assigned to either observation (n = 59) or XELOX (n = 54). Compliance was poor, 93% allocated chemotherapy started and 48% completed six cycles. Protocolised dose reductions in XELOX were 39%, and levels of G3/G4 toxicity 40%. After a median follow-up of 44.8 months, 16 patients (27%) in the observation arm had relapsed or died compared with 12 patients (22%) in XELOX. The 3-year DFS rate was 78% with XELOX and 71% with observation [hazard ratio (HR) for DFS = 0.80; 95% confidence interval (CI) 0.38-1.69; P = 0.56]. The 3-year OS for XELOX and observation were 89% and 88%, respectively (HR for OS = 1.18; 95% CI 0.43-3.26; P = 0.75). CONCLUSIONS: The observed improvement in DFS for adjuvant XELOX and similar OS were not statistically significant, as expected given the small number of patients and consequent low power. Our findings support the need for trials that test the role of neoadjuvant chemotherapy. CLINICALTRIALSGOV IDENTIFIER: NCT00427713.

Tumour- and treatment-related colostomy rates following mitomycin C or cisplatin chemoradiation with or without maintenance chemotherapy in squamous cell carcinoma of the anus in the ACT II trial.

BACKGROUND: Squamous cell carcinoma of the anus (SCCA) is highly sensitive to chemoradiation (CRT) which achieves good loco-regional control and preserves anal function. However, some patients require permanent stoma formation either as a result of surgery on relapse, poor anal function or treatment-related symptoms. Our aim was to determine patient, tumour and treatment-related colostomy rates following CRT and maintenance chemotherapy in the ACT II trial. PATIENTS AND METHODS: The ACT II trial recruited 940 patients comparing 5FU-based CRT using cisplatin (CisP) or mitomycin C (MMC) with or without additional maintenance chemotherapy. We investigated the association between colostomy-free survival (CFS) and progression-free survival (PFS) with age, gender, T-stage, N-stage, treatment and baseline haemoglobin. RESULTS: The median follow-up was 5.1 years (n = 884 evaluable/940); tumour site canal (84%), margin (14%); stage T1/T2 (52%), T3/T4 (46%); N+ (32%), N0 (62%). Twenty out of 118 (17%) colostomies fashioned before CRT were reversed within 8 months. One hundred and twelve patients had a post-treatment colostomy due to persistent disease (98) or morbidity (14). Fifty-two per cent (61/118) of all pre-treatment colostomies were never reversed. The 5-year CFS rates were 68% MMC/Maint, 70% CisP/Maint, 68% MMC/No-maint and 65% CisP/No-maint. CRT with CisP did not improve CFS when compared with MMC (hazard ratio: 1.04, 95% confidence interval: 0.82-1.31, P = 0.74). The 5-year CFS rates were higher for T1/T2 (79%) than T3/T4 (54%) tumours and higher for node-negative (72%) than node-positive (60%) patients. Significant predictors of CFS were gender, T-stage and haemoglobin, while treatment factors had no impact on outcome. Similar associations were found between PFS and tumour/treatment-related factors. CONCLUSIONS: The majority (52%) of pre-treatment colostomies were never reversed. Neither CRT with 5FU/CisP nor maintenance chemotherapy impacted on CFS. The low risk of colostomy for late effects (1.7%) is likely to be associated with the modest total radiotherapy dose. The predictive factors for CFS were T-stage, gender and baseline haemoglobin. CLINICAL TRIAL REGISTRATION NUMBER: ISRCTN 26715889.

Neutrophil:lymphocyte ratio as a simple and novel biomarker for prediction of locoregional recurrence after chemoradiotherapy for squamous cell carcinoma of the anus.

AIM: The neutrophil: lymphocyte ratio (NLR) is a prognostic marker in several malignancies. This study assessed whether it can be used as a predictor of loco-regional recurrence after chemoradiotherapy for anal squamous cell carcinoma (SCC). METHOD: Patients treated with curative intent between 1 January 2004 and 31 December 2011 were identified. Pretreatment blood tests and radiological staging were available from multidisciplinary meeting records. The NLR was calculated from pretreatment blood tests. The relationship between the NLR and clinicopathological parameters was analysed. Modified receiver-operating characteristics curves were constructed to determine the cut-off NLR to dichotomise the data for survival analyses. The measured cut-off was 4.75. RESULTS: Ninety-two patients were identified. Pretreatment T-stages were T1 (n = 7), T2 (n = 36), T3 (n = 35) and T4 (n = 14) and pretreatment N stages were N0 (n = 62) and N+ disease (n = 30). The NLR was significantly higher in N+ disease (P = 0.014) and in patients who developed recurrence (P = 0.003). On multivariate analysis, the NLR maintained its significance, with a hazard ratio (HR) of 1.38 (95% CI = 1.195-1.594) (P < 0.0001). An elevated NLR was associated with worse overall (P < 0.0001) and cancer-specific (P < 0.0001) survival. Multivariate Cox regression analysis demonstrated that an elevated NLR was prognostic for overall survival (HR = 6.381, 95% CI = 1.742-23.372, P = 0.005) and for cancer-specific survival (HR = 10.613, 95% CI = 1.968-57.241, P = 0.006). CONCLUSION: Pretreatment NLR may be a simple biomarker for predicting disease recurrence and overall and cancer-specific survival after potentially curative chemo-radiotherapy for SCC of the anus.

The rising incidence of anal cancer in England 1990-2010: a population-based study.

AIM: Although anal cancer is rare, its incidence has been reported to be rising in several countries. This study aimed to determine whether there have been any changes in incidence over time in England. METHOD: In the cancer registry component of the English National Cancer Data Repository, 13 940 patients were identified with a primary diagnosis of anal cancer made between 1990 and 2010. Tumours were grouped according to the ICD-O morphology codes into squamous cell carcinoma, basaloid and cloacogenic carcinoma, adenocarcinoma and other cancer types. The incidence over this period was investigated in relation to type of tumour, age and sex. RESULTS: In men there was a 69% increase in squamous cell anal carcinoma from 0.43 per 100 000 population in 1990-94 to 0.73 in 2006-10. For women these rates were 0.50 in 1990-94 and 1.13 in 2006-10, a rise of 126%. CONCLUSION: The study showed that between 1990 and 2010 there was a substantial rise in the incidence of anal cancer in England. This effect was more marked in women than men.

The English national low rectal cancer development programme: key messages and future perspectives.

AIM: Adenocarcinoma of the lower rectum is clinically challenging because of the need to choose between a wide excision to achieve oncological clearance, on the one hand, and sphincter conservation to maintain anal function, on the other. The English National Low Rectal Cancer Development Programme (LOREC) was developed under the auspices of the Association of Coloproctology of Great Britain and Ireland and the English National Cancer Action Team to improve the outcome of low rectal cancer in England. METHOD: LOREC was initiated focusing on preoperative imaging, selective neoadjuvant therapy, optimal surgical treatment and detailed pathological assessment of the excised specimen. Its key elements were 1-day multidisciplinary team (MDT) workshops, cadaveric surgical training, surgical mentoring, pathological audit and radiological workshops. RESULTS: Overall, 147 (89.6%) of 164 MDTs from 151 National Health Service (NHS) Trusts (some with two MDTs) in England participated in 15 workshops in Basingstoke or Leeds. In addition, 112 surgeons attended a 1-day cadaveric training programme in Bristol, Newcastle or Nottingham, with the main focus on extralevator abdominoperineal excision and pelvic reconstruction, with input from anatomists and from colorectal and plastic surgeons. CONCLUSION: Optimal staging, selective preoperative chemoradiotherapy and precise surgery were considered as crucial to improve the outcome for patients with low rectal cancer.

Hitting the Target: Developing High-quality Evidence for Proton Beam Therapy Through Randomised Controlled Trials.

The National Health Service strategy for the delivery of proton beam therapy (PBT) in the UK provides a unique opportunity to deliver high-quality evidence for PBT through randomised controlled trials (RCTs). We present a summary of three UK PBT RCTs in progress, including consideration of their key design characteristics and outcome assessments, to inform and support future PBT trial development. The first three UK multicentre phase III PBT RCTs (TORPEdO, PARABLE and APPROACH), will compare PBT with photon radiotherapy for oropharyngeal squamous cell carcinoma, breast cancer and oligodendroglioma, respectively. All three studies were designed by multidisciplinary teams, which combined expertise from clinicians, clinical trialists and scientists with strong patient advocacy and guidance from national radiotherapy research networks and international collaborators. Consistent across all three studies is a focus on the reduction of long-term radiotherapy-related toxicities and an evaluation of patient-reported outcomes and health-related quality of life, which will address key uncertainties regarding the clinical benefits of PBT. Innovative translational components will provide insights into mechanisms of toxicity and help to frame the key future research questions regarding PBT. The UK radiotherapy research community is developing and delivering an internationally impactful PBT research portfolio. The combination of data from RCTs with prospectively collected data from a national PBT outcomes registry will provide an innovative, high-quality repository for PBT research and the platform to design and deliver future trials of PBT.

Adenocarcinoma of the anal canal - a systematic review.

AIM: The prognosis of anal adenocarcinoma is poor and the management remains controversial. We carried out a literature review to identify current practice in the management of anal adenocarcinoma. METHOD: A systematic review of the literature was performed for studies in the English language published between 1950 and 2011. All those that focused on the management of anal adenocarcinoma were considered for inclusion. RESULTS: Sixteen retrospective observational studies were identified; no randomized trials were found. Most of the studies contained small numbers of patients due to the rarity of anal adenocarcinoma. Treatment included local excision), radiotherapy, chemotherapy, chemoradiotherapy and abdominoperineal excision. Most studies concluded that a multimodality approach, combining radical surgical resection with neoadjuvant/adjuvant chemoradiotherapy was the optimal management strategy. CONCLUSION: The prognosis of anal adenocarcinoma is poor, and there is little information on the optimal management. The relevant studies indicate that a combination of radical surgical resection and pre- or postoperative chemoradiotherapy offers the best chance of survival.

The oncological outcome after right hemicolectomy and accuracy of CT scan as a preoperative tool for staging in right sided colonic cancers.

AIM: Neoadjuvant chemotherapy may have a role in the management of colonic carcinoma but clinical trials are required to determine whether this approach is superior to the standard policy of radical surgery, high-quality histopathology and selective postoperative chemotherapy. The selection of appropriate patients for such trials will depend on accurate locoregional staging of disease by preoperative CT scanning. We studied the outcome after radical right hemicolectomy and assessed the accuracy of preoperative CT scans in the prediction of postoperative pathology. METHOD: A retrospective analysis of right hemicolectomies performed with curative intent for colon cancer under the care of a single colorectal surgeon (D.J.A.) was performed. Preoperative CT-proven Dukes D patients were excluded. Patient demographics, postoperative histology, use of adjuvant chemotherapy and survival data were collected. Kaplan-Meier curves were constructed and log-rank testing was performed to compare cancer-specific survival. Fifty patients had their preoperative CT scan images reviewed by two radiologists both blinded to the results of the postoperative histology. The accuracy of preoperative CT for T and N staging was studied. A P-value of < 0.05 was significant. RESULTS: There were 136 patients (79 women). Median age was 76 (interquartile ratio 67-82) years. Median period of follow-up was 72 (interquartile ratio 39-92) months. There were 56 deaths (39 medical, 16 oncological and 1 postoperative). There were three groups of patients: node negative (n = 84), node positive with postoperative adjuvant chemotherapy (n = 30) and node positive without chemotherapy (n = 22). Five-year cancer-specific survival for node negative disease was 84% and was poorer for node positive patients who received adjuvant chemotherapy when compared with those who did not (62 vs 72%, P-value = 0.046 on log-rank testing). Sensitivity, specificity, positive and negative predictive value of CT scan for tumour (T) stage were 90, 33, 86 and 43% respectively, while that for nodal (N) stage was 83, 38, 57 and 69%, respectively. CONCLUSION: CT scan has limited accuracy in predicting those patients with advanced locoregional disease who might benefit from neoadjuvant treatment. When this finding is combined with relatively high cancer-specific survival with surgery alone the impact of adjuvant chemotherapy on survival after radical surgery for right colon carcinoma may be marginal.

Defunctioning stomas prior to chemoradiation for anal cancer are usually permanent.

AIM: A few patients with anal cancer will require a defunctioning stoma prior to chemoradiotherapy (CRT). The purpose of this retrospective review was to determine the frequency with which a pretreatment stoma was subsequently reversed. METHOD: Between 1997 and 2007, 46/344 patients who were treated for anal cancer underwent a defunctioning stoma prior to CRT. Thirty-five of these were treated with curative intent. RESULTS: Of the 35 patients, 16 patients had T4, 17 T3 and 2 T2 disease. Sixteen were node positive. The average tumour size was 7 cm. The median interval between stoma formation and CRT was 6 (4-20) weeks. The median follow up was 26 (2-80) months. A defunctioning stoma was performed for rectovaginal fistula or risk of fistula in 18 and severe local symptoms in 17. Seven (20%) patients had the stoma reversed subsequently. The reasons for nonreversal were progressive disease (n = 9), persistent fistula (n = 3), predicted poor function (n = 4), cavity formation (n = 1), fibrosis (n = 3), death from another cause (n = 2), patient choice (n = 3) and salvage surgery (n = 2). The overall 3-year survival was only 48%, explained by the advanced stage of disease at presentation. CONCLUSION: Most patients who undergo a defunctioning stoma before CRT will not undergo subsequent reversal. The patient should therefore be informed that the stoma is likely to be permanent and this should be taken into account when considering the type and site of stoma to be formed.

The Long and the Short of it: the Role of Short-course Radiotherapy in the Neoadjuvant Management of Rectal Cancer.

Total mesorectal excision is the cornerstone of treatment for rectal cancer. Multiple randomised trials have shown a reduction in local recurrence rates with the addition of preoperative radiotherapy, either as a 1-week hypofractionated short-course (SCRT) or a conventionally fractionated long-course (LCRT) schedule with concurrent chemotherapy. There is also increasing interest in the addition of neoadjuvant chemotherapy to radiotherapy with the aim of improving disease-free survival. The relative use of SCRT and LCRT varies considerably across the world. This is reflected in, and is probably driven in part by, disparity between international guideline recommendations. In addition, different approaches to treatment may exist both between and within countries, with variation related to patient, disease and treatment centre and financial factors. In this review, we will specifically focus on the use of SCRT for the treatment of rectal cancer. We will discuss the literature base and current guidelines, highlighting the challenges and controversies in clinical application of this evidence. We will also discuss potential future applications of SCRT, including its role in optimisation and intensification of treatment for rectal cancer.

One millimetre is the safe cut-off for magnetic resonance imaging prediction of surgical margin status in rectal cancer.

BACKGROUND: A pathologically involved margin in rectal cancer is defined as tumour within 1 mm of the surgical resection margin. There is no standard definition of a predicted safe margin on magnetic resonance imaging (MRI). The aim of this study was to assess which cut-off (1, 2 or 5 mm) was the best predictor of local recurrence based on preoperative MRI assessment of the circumferential resection margin (CRM). METHODS: Data were collected prospectively on the distance between the tumour and mesorectal fascia for patients with documented radiological margin status in the MERCURY study. Positive margin and local recurrence rates were compared for MRI distances from the tumour to the mesorectal fascia of 1 mm or less, more than 1 mm up to 2 mm, more than 2 mm up to 5 mm, and more than 5 mm. The Cox proportional hazard regression method was used to determine the effect of level of margin involvement on time to local recurrence. RESULTS: Univariable analysis showed that, relative to a distance measured by MRI of more than 5 mm, the hazard ratio (HR) for local recurrence was 3·90 (95 per cent confidence interval 1·99 to 7·63; P < 0·001) for a margin of 1 mm or less, 0·81 (0·36 to 1·85; P = 0·620) for a margin of more than 1 mm up to 2 mm, and 0·33 (0·10 to 1·08; P = 0·067) for a margin greater than 2 mm up to 5 mm. Multivariable analysis of the effect of MRI distance to the mesorectal fascia and preoperative treatment on local recurrence showed that a margin of 1 mm or less remained significant regardless of preoperative treatment (HR 3·72, 1·43 to 9·71; P = 0·007). CONCLUSION: For preoperative staging of rectal cancer, the best cut-off distance for predicting CRM involvement using MRI is 1 mm. Using a cut-off greater than this does not appear to identify patients at higher risk of local recurrence.

Multicentre Investigation of Prognostic Factors Incorporating p16 and Tumour Infiltrating Lymphocytes for Anal Cancer After Chemoradiotherapy.

AIMS: Anal squamous cell carcinomas (ASCC) are strongly associated with human papillomaviruses. Standard of care is chemoradiotherapy at uniform doses with no treatment stratification. Immunohistochemical staining for p16INK4A (p16), a surrogate for human papillomaviruses, is prognostic for outcomes. We investigated this alongside clinical-pathological factors, including tumour infiltrating lymphocyte (TIL) scores. MATERIALS AND METHODS: Using an independent, multicentre cohort of 257 ASCC treated with chemoradiotherapy, pretreatment biopsies were stained and scored for p16 and TIL. Kaplan-Meier curves were derived for outcomes (disease-free survival [DFS], overall survival and cancer-specific survival), by stage, p16 and TIL scores and Log-rank tests were carried out to investigate prognostic effect. A multivariate analysis was carried out using Cox regression. RESULTS: Stage, sex, p16 and TILs were independently prognostic. Hazard ratios for death (overall survival) were 2.51 (95% confidence interval 1.36-4.63) for p16 negative versus p16 positive, 2.17 (1.34-3.5) for T3/4 versus T1/2, 2.42 (1.52-3.8) for males versus females and 3.30 (1.52-7.14) for TIL1 versus TIL3 (all P < 0.05). CONCLUSIONS: We have refined prognostic factors in ASCC. p16 adds to stratification by stage with respect to DFS in early disease and overall survival/DFS in locally advanced cancers. Our data support the role of the host immune response in mediating outcomes. These factors will be prospectively evaluated in PLATO (ISRCTN88455282).