Early Mortality after Radical Radiotherapy in Head and Neck Cancer - A Nationwide Analysis from the Danish Head and Neck Cancer Group (DAHANCA) Database

AIMS

Curative-intent radiotherapy (RT) or chemoradiation (CRT) of squamous cell carcinoma of the head and neck (HNSCC) produces high survival rates, but is associated with substantial toxicity. However, there are no commonly accepted quality metrics for early mortality in radiation oncology. To assess the applicability of early mortality as a clinical quality indicator, this study investigated the temporal distribution, risk factors and trends of 90- and 180-day overall and non-cancer mortality in a nationwide cohort of HNSCC patients treated with RT/CRT.

MATERIALS AND METHODS

Information on all HNSCC patients treated with curative-intent RT/CRT in Denmark between 2000 and 2017 was obtained from the national Danish Head and Neck Cancer Group clinical database. Deaths in patients with residual or recurrent disease after RT/CRT were classified as cancer-related. Possible risk factors were investigated using logistic regression analysis.

RESULTS

Data from 11 419 patients were extracted. In total, 90- and 180-day mortality risks were 3.1% and 7.1%, respectively. There was a uniform temporal distribution of 180-day mortality. In multivariable analysis, increasing age, stage, performance status, earlier treatment year and hypopharyngeal cancer were significantly associated with an increased risk (P < 0.05). Risk factor estimates were comparable for 90- versus 180-day mortality as well as for overall versus non-cancer mortality. Between 2000 and 2017 there was a significant decrease in 180-day mortality, which was driven by a reduction in cancer-related events.

CONCLUSION

The distribution of 180-day overall and non-cancer mortality did not indicate a well-defined early high-risk period. Moreover, risk factor estimates were highly similar across risk periods and groups. Taken together, our findings question the applicability of early mortality as a standard metric for treatment-associated toxicity.

NTCP model validation method for DAHANCA patient selection of protons versus photons in head and neck cancer radiotherapy

Introduction: Prediction models using logistic regression may perform poorly in external patient cohorts. However, there is a need to standardize and validate models for clinical use. The purpose of this project was to describe a method for validation of external NTCP models used for patient selection in the randomized trial of protons versus photons in head and neck cancer radiotherapy, DAHANCA 35. Material and methods: Organs at risk of 588 patients treated primarily with IMRT in the randomized controlled DAHANCA19 trial were retrospectively contoured according to recent international recommendations. Dose metrics were extracted using MatLab and all clinical parameters were retrieved from the DAHANCA database. The model proposed by Christianen et al. to predict physician-rated dysphagia was validated through the closed testing, where change of the model intercept, slope and individual beta's were tested for significant prediction improvements. Results: Six months prevalence of dysphagia in the validation cohort was 33%. The closed testing procedure for physician-rated dysphagia showed that the Christianen et al. model needed an intercept refitting for the best match for the Danish patients. The intercept update increased the risk of dysphagia for the validation cohort by 7.9 ± 2.5% point. For the raw model performance, the Brier score (mean squared residual) was 0.467, which improved significantly with a new intercept to 0.415. Conclusions: The previously published Dutch dysphagia model needed an intercept update to match the Danish patient cohort. The implementation of a closed testing procedure on the current validation cohort allows quick and efficient validation of external NTCP models for patient selection in the future.

Levels of Tissue Inhibitor of Metalloproteinases 1 in Plasma and Urine from Patients with Bladder Cancer

Aim

To assess the potential use of plasma and urine levels of tissue inhibitor of metalloproteinases 1 (TIMP-1) in urothelial cancer.

Methods

TIMP-1 levels were determined in urine and plasma from healthy donors (n=26), patients with bacterial bladder infection (n=24), urothelial bladder adenoma (n=3) or adenocarcinoma (n=7).

Results

Free and total TIMP-1 in plasma were weakly but significantly correlated with age; urinary TIMP-1 was not. A strong correlation between free and total TIMP-1 in plasma was observed, with an average ratio of 0.85. No correlation between total TIMP-1 in urine and plasma was found (p=0.55). No significant differences in free or total TIMP-1 in plasma were found between healthy individuals, patients with cystitis or bladder cancer (p=0.4). Urinary TIMP-1 levels were significantly increased in patients with cystitis (p=0.001). No apparent differences in TIMP-1 levels were found in patients with bladder cancer at different stages.

Conclusion

Our previous observation of a weak but significant correlation between plasma TIMP-1 and age was confirmed. Likewise, an association between free and total TIMP-1 in plasma with a ratio of 0.85 was established. No correlation between plasma and urine TIMP-1 was found. Measurement of TIMP-1 in plasma and/or urine is apparently not useful for the identification of bladder cancer.

Waiting times for diagnosis and treatment of head and neck cancer in Denmark in 2010 compared to 1992 and 2002

BACKGROUND AND AIM

Significant tumour progression was observed during waiting time for treatment of head and neck cancer. To reduce waiting times, a Danish national policy of fast track accelerated clinical pathways was introduced in 2007. This study describes changes in waiting time and the potential influence of fast track by comparing waiting times in 2010 to 2002 and 1992.

METHODS

Charts of all new patients diagnosed with squamous cell carcinoma of the oral cavity, pharynx and larynx at the five Danish head and neck oncology centres from January to April 2010 (n=253) were reviewed and compared to similar data from 2002 (n=211) and 1992 (n=168).

RESULTS

The median time to diagnosis was 13 days (2010) versus 17 days (2002; p<0.001) and 20 days (1992; p<0.001). Median days from diagnosis to treatment start were 25 (2010) versus 47 (2002; p<0.001) and 31 (1992; p<0.001). Total pre-treatment time was median 41 days in 2010 versus 69 days (2002) (p<0.001) and 50 days (1992; p<0.001). Significantly more diagnostic imaging was done in 2010 compared to 2002 and 1992. When compared to current fast track standards the adherence to diagnosis improved slightly from 47% (1992) to 51% (2002) and 64% (2010); waiting time for radiotherapy was within standards for 7%, 1% and 22% of cases, respectively; waiting time for surgery was within standards for 17%, 22% and 48%, respectively.

CONCLUSION

The study showed a significant reduction in delay of diagnosis and treatment of head and neck cancer in 2010, but still less than half of all patients start treatment within the current standards.

Allelic deletions of cell growth regulators during progression of bladder cancer

Cell growth regulators include proteins of the p53 pathway encoded by the genes CDKN2A (p16, p14arf), MDM2, TP53, and CDKN1A (p21) as well as proteins encoded by genes like RB1, E2F, and MYCL. In the present study we investigated allelic deletions of all these genes in each recurrent bladder tumor from well-defined clinical material with more than 3 years of follow-up. We followed three groups (22 or 23 patients/group) of patients with: (a) recurrent noninvasive tumors (Ta); (b) primary muscle-invasive tumors (T2-T4); and (c) progressing tumors (Ta/T1 --> T2/T4). We found a significant difference in the numbers of gene loci hit by deletions muscle-invasive versus noninvasive tumors (P = 0.0000002), with the genes most often hit by deletions in muscle-invasive tumors being TP53, RB1, and MYCL. A number of novel findings were made. Losses of MYCL and RB1 alleles were more pronounced in patients having concomitant field disease because 11 of 14 informative cases showed losses compared with 3 of 8 cases without field disease. A more pronounced deletion of TP53 (P = 0.002) and RB1 (P = 0.02) was found in the progressing tumor group compared with the recurrent noninvasive group, and, finally, the combined loss of TP53 and RB1 was present only in the progressing tumor or muscle-invasive groups. Deletion of two or more loci in TP53, MYCL, RB1, and CDKN2A was found in 10 patients in the progressing tumor group and in only 1 patient in the recurrent noninvasive group (P = 0.004). The data demonstrate that a characteristic difference between recurrent noninvasive and recurrent progressing bladder tumors is loss of cell cycle-regulatory genes in the latter group.