Neoadjuvant Chemoradiotherapy for Oral Cavity Cancer: Predictive Factors for Response and Interim Analysis of the Prospective INVERT-Trial

A Primer to Experimental and Nonexperimental Quantitative Research: The Example Case of Tobacco-Related Mouth Cancer

OBJECTIVES

To present a comprehensive overview of key constructs of experimental and nonexperimental quantitative research, drawing on one example case from cancer care.

DATA SOURCES

Published scientific articles, research textbooks, and expert advice were used in this article.

CONCLUSION

Quantitative research turns information collected about people or about processes into numerical data. Depending on the underlying purpose, the goal is to address questions that have to do with intervention, prognosis, causation, association, description, or assessment. In experimental research, an intervention is manipulated. True experimental research (randomized controlled trial) controls confounding variables via use of both randomization and a control group; quasi-experimental research misses one or both of these elements. In either case, the aim is to generate evidence to confidently say that an intervention is the true cause of an observed outcome. Nonexperimental research is multifaceted. Cohorts and case-control studies can be used to test cause-and-effect relationships where experimental research is unethical or impractical. Correlational research aims to explore possible associations (exploratory) or help anticipate outcomes (predictive) and, quite often, is the precursor of experimental research. Descriptive research (simple, comparative, survey, retrospective chart review) can be used to describe and assess situations, conditions, or behaviors.

IMPLICATIONS FOR NURSING PRACTICE

Understanding the different aims and goals of the different types of quantitative research can help increase capacity and confidence in understanding, appraising, and applying quantitative evidence among health care students, professionals, and novice researchers in the quest for the provision of quality cancer care.

Fibroblasts as Turned Agents in Cancer Progression

Differentiated epithelial cells reside in the homeostatic microenvironment of the native organ stroma. The stroma supports their normal function, their G0 differentiated state, and their expansion/contraction through the various stages of the life cycle and physiologic functions of the host. When malignant transformation begins, the microenvironment tries to suppress and eliminate the transformed cells, while cancer cells, in turn, try to resist these suppressive efforts. The tumor microenvironment encompasses a large variety of cell types recruited by the tumor to perform different functions, among which fibroblasts are the most abundant. The dynamics of the mutual relationship change as the sides undertake an epic battle for control of the other. In the process, the cancer “wounds” the microenvironment through a variety of mechanisms and attracts distant mesenchymal stem cells to change their function from one attempting to suppress the cancer, to one that supports its growth, survival, and metastasis. Analogous reciprocal interactions occur as well between disseminated cancer cells and the metastatic microenvironment, where the microenvironment attempts to eliminate cancer cells or suppress their proliferation. However, the altered microenvironmental cells acquire novel characteristics that support malignant progression. Investigations have attempted to use these traits as targets of novel therapeutic approaches.