Head-to-head comparison of three experimental methods of quantifying competitive fitness in C. elegans.

Organismal fitness is relevant in many contexts in biology. The most meaningful experimental measure of fitness is competitive fitness, when two or more entities (e.g., genotypes) are allowed to compete directly. In theory, competitive fitness is simple to measure: an experimental population is initiated with the different types in known proportions and allowed to evolve under experimental conditions to a predefined endpoint. In practice, there are several obstacles to obtaining robust estimates of competitive fitness in multicellular organisms, the most pervasive of which is simply the time it takes to count many individuals of different types from many replicate populations. Methods by which counting can be automated in high throughput are desirable, but for automated methods to be useful, the bias and technical variance associated with the method must be (a) known, and (b) sufficiently small relative to other sources of bias and variance to make the effort worthwhile. The nematode Caenorhabditis elegans is an important model organism, and the fitness effects of genotype and environmental conditions are often of interest. We report a comparison of three experimental methods of quantifying competitive fitness, in which wild-type strains are competed against GFP-marked competitors under standard laboratory conditions. Population samples were split into three replicates and counted (1) "by eye" from a saved image, (2) from the same image using CellProfiler image analysis software, and (3) with a large particle flow cytometer (a "worm sorter"). From 720 replicate samples, neither the frequency of wild-type worms nor the among-sample variance differed significantly between the three methods. CellProfiler and the worm sorter provide at least a tenfold increase in sample handling speed with little (if any) bias or increase in variance.

Phase III randomized trial of induction chemotherapy in patients with N2 or N3 locally advanced head and neck cancer.

PURPOSE: Induction chemotherapy (IC) before radiotherapy lowers distant failure (DF) rates in locally advanced squamous cell carcinoma of the head and neck (SCCHN). The goal of this phase III trial was to determine whether IC before chemoradiotherapy (CRT) further improves survival compared with CRT alone in patients with N2 or N3 disease. PATIENTS AND METHODS: Treatment-naive patients with nonmetastatic N2 or N3 SCCHN were randomly assigned to CRT alone (CRT arm; docetaxel, fluorouracil, and hydroxyurea plus radiotherapy 0.15 Gy twice per day every other week) versus two 21-day cycles of IC (docetaxel 75 mg/m(2) on day 1, cisplatin 75 mg/m(2) on day 1, and fluorouracil 750 mg/m(2) on days 1 to 5) followed by the same CRT regimen (IC + CRT arm). The primary end point was overall survival (OS). Secondary end points included DF-free survival, failure pattern, and recurrence-free survival (RFS). RESULTS: A total of 285 patients were randomly assigned. The most common grade 3 to 4 toxicities during IC were febrile neutropenia (11%) and mucositis (9%); during CRT (both arms combined), they were mucositis (49%), dermatitis (21%), and leukopenia (18%). Serious adverse events were more common in the IC arm (47% v 28%; P = .002). With a minimum follow-up of 30 months, there were no statistically significant differences in OS (hazard ratio, 0.91; 95% CI, 0.59 to 1.41), RFS, or DF-free survival. CONCLUSION: IC did not translate into improved OS compared with CRT alone. However, the study was underpowered because it did not meet the planned accrual target, and OS was higher than predicted in both arms. IC cannot be recommended routinely in patients with N2 or N3 locally advanced SCCHN.

A randomized validation study comparing embedded versus extracted FACT Head and Neck Symptom Index scores.

OBJECTIVE: To evaluate the impact of administration context (embedded versus stand-alone) on the reliability and validity of the FACT Head and Neck Symptom Index (FHNSI). METHODS: Ninety-eight patients with head and neck cancer were randomized to one of two assessment conditions to evaluate the FHNSI's context (items administered embedded within the FACT-H&N or as stand-alone scale) and order of administration in the battery. RESULTS: Planned comparisons on the item and scale levels revealed no systematic order or context differences. The embedded and stand-alone versions of the FHNSI showed high internal consistency (Cronbach's alpha 0.79-0.87). Correlations were high between the FHNSI versions and the physical and functional well-being scales of the FACT-H&N (0.70-0.84) and measures of pain intensity (-0.73, -0.74) and depression (-0.71, -0.74); moderate to large with the Performance Status Scale for Head and Neck subscales (PSS-HN; 0.46-0.71); and low with an anxiety measure (0.30, 0.34). Both FHNSI versions differentiated patients grouped by performance status (p < .0001, p < .0001) and global rating of change (p < .0001, p < 0.01). The FHNSI's minimally important difference range was 3-4 points. CONCLUSION: The FHNSI is a reliable and valid symptom index, which can be administered alone or scored using items embedded within the FACT-H&N.