Learning Objectives
By the end of this section, you will be able to:
- Describe the diagnostics and laboratory values of select cancers
- Summarize systems of staging cancers and grading tumors
- Discuss strategies for cancer prevention
Diagnostics for cancer identification encompass imaging studies such as computed tomography (CT) scans and magnetic resonance imaging (MRI) that are classically used to detect alterations to organs and tissues along with identifying the presence of a malignant mass. Laboratory testing includes biomarkers specific to the presence of specific types of cancer. Biopsies are used to obtain a sample of suspected cancerous tissue and examine its properties under a microscope, evaluating cellular characteristics unique to cancerous change in cells.
Once detected and evaluated, a stage and grade are assigned to the cancerous cells. These assignments assist the provider in guiding treatment, predicting the outcome, understanding how quickly or aggressively the cancerous cells may grow and spread, and the likelihood of complications due to these factors.
Cancer prevention strategies center around risk reduction. A controllable and well-established primary prevention method for reducing risk is lifestyle modifications to include healthier diet options, routine physical activity, and avoiding carcinogens such as tobacco and alcohol. Vaccination against carcinogenic viruses, notably human papillomavirus (HPV) and hepatitis B (HBV), is another important primary prevention strategy. Secondary prevention, including early detection with screenings for cancers, is the next-best option to detect cancer early and limit its ability to grow and spread. Examples of secondary prevention include mammograms for breast cancer, colonoscopies for colorectal cancer, and the cotest for HPV and the Pap test for cervical cancer.
Detecting and Diagnosing Cancer
Detection and diagnosis involve a combination of screening tests at recommended intervals, imaging studies, and often a biopsy of the suspected malignancy. An example of this process is the use of mammography to detect breast cancer in females and males who are genetically at risk (Figure 31.10). Low-dose CT scanning helps detect lung cancer in individuals who are at greater risk due to long-term inhaled chemical exposure. Endoscopies, such as a colonoscopy for colorectal cancer, are performed to detect precancerous or cancerous polyps and lesions. Pathologists can examine biopsied cells for abnormalities, such as is done in a Pap test or Pap smear for cervical cancer. Physical assessment of the skin helps to detect skin cancer. Blood tests, such as the prostate-specific antigen test for prostate cancer, help detect tumor markers. Genetic testing is used to screen for genetic mutations that affect development of certain cancer types, and when applicable, can also be used determine the best course of treatment.
Diagnostic Tests
X-rays are used to detect abnormalities that a tumor would create in soft tissues and bones. However, x-rays are not a recommended diagnostic tool for detection of other types of cancers, such as tumors of the lungs. For more detailed images of deeper structures and organs, CT scans can be performed. Even when they cannot precisely detect a tumor, a CT scan can often show abnormalities that lead to further testing or indicate the need for a biopsy. MRI also creates detailed images and is good for detecting abnormalities in soft tissues. Rather than being performed to initially detect cancer, MRI is a good diagnostic tool to gather additional imaging of suspected tumors. Ultrasound uses sound waves to create images from inside the body, making it useful for guiding biopsies by showing the tumor location and allowing precision when obtaining tissue samples.
Blood tests are useful to detect specific tumor markers, proteins, or substances that indicate the likely presence of cancer. Additionally, blood tests are often used to gauge the effectiveness of treatment or during periods of remission to determine recurrence.
A biopsy is the removal of a tissue or cell sample for the pathologist to examine for abnormal cells. The sample can be removed using a needle or during a surgical or endoscopic procedure. A biopsy is the most reliable method to confirm a cancer diagnosis.
Cancer Staging and Grading
Grading and staging systems standardize diagnosis, the likely prognosis, and the treatments to consider. The term grading describes the cellular characteristics and aggressiveness of cancer cells and, by extension, how sensitive the cells will be to treatment. Tumor grading scales provide a grade from GX to G4, where GX denotes inability to assess the grade of the cells (Figure 31.11). Undifferentiated cells (G4), indicate that cells, when examined under a microscope, do not resemble the tissue cells from which they came.
Cell differentiation is the process cells undergo to become specialized in both structure and function. Specialized cell examples are muscle cells, nerve cells, and skin cells. This form and function allows the cells to form a group and perform as their designated tissue or organ should. If the pathologist examines a sample of healthy tissue that was biopsied from a lung, the tissue should be well differentiated. In this example, a well differentiated cell should look the same as any other sample of lung tissue. A healthy cell is matured. It is a specialized cell designed to function in the respiratory process. Even if the pathologist looked at biopsies obtained from many different lung sites, all lung cells should be very similar in appearance—e.g., uniform size, shape, and nucleus. Cancer cells, however, will have a different appearance than normal cells; pathologists use these differences to grade cancer in each patient.
The staging system is different for every type of cancer, but it generally refers to whether the tumor is confined to one space or has spread to other areas of the body. The basic TNM system (tumor, node, and metastasis) represents the anatomic extent of solid tumors, and it gauges the size and extent of tumor (T), lymph node involvement (N), and systemic involvement or metastasis (M) for prognostic implications. Tumor invasiveness is denoted with a number of 1 through 4 (T1, T2, T3, T4). The term carcinoma in situ indicates that abnormal cells have been found but have not spread (Figure 31.12).
The TMN system does not apply to leukemia because it is a blood cancer and not a cancer with a tumor. There are other staging systems that can also be applied to specific types of cancer, such as skin or colon cancer. When the tumor, lymph nodes, or metastasis cannot be assessed, this is denoted with an X (TX, NX, MX). An example of the TMN system application is shown in Table 31.1. This system is then applied to determine the cancer stage.
| Bladder Cancer (Transitional Cell Carcinoma) | Skin Cancer (Melanoma) |
|---|---|
| T1 N0 M0 Stage I | T2 N1 M0 Stage IIA |
| T1: the cancer has invaded the connective tissue of the bladder lining but has not reached the muscle layer N0: no regional lymph node involvement M0: no distant metastasis |
T2: the melanoma is between 1.01 and 2.0 millimeters thick N1: cancer has spread to one nearby lymph node M0: no distant metastasis |
The TNM system is only one method for assessing cancer and is only a guideline for prognosis and treatment considerations. The application of the system varies according to each type of tumor, and the guidelines for staging are extensive.
Link to Learning
Nurses are responsible for understanding what the staging indicates but are not responsible for knowing the details for each type of cancer. Read more about cancer staging systems developed by the American Joint Committee on Cancer (AJCC).
Cancer Prevention
Prevention focuses on reducing the risk of developing cancer. This involves lifestyle changes to reduce general cancer risk as well as specific interventions to reduce the risk of cancers known to affect certain populations. There are three levels of prevention: primary, secondary, and tertiary.
Primary Prevention
Avoiding known risk factors to prevent the development of disease is ideal. Primary prevention promotes healthy lifestyle choices. Moderate or eliminate tobacco exposure, alcohol intake, and the intake of fatty or processed foods (Figure 31.13). Engage in regular physical activity and attain or maintain an acceptable weight. Ensure all recommended vaccines are kept up to date. Consistently and frequently eat foods rich in antioxidants and fiber, including fruits and vegetables.
Secondary Prevention
Secondary prevention involves detecting cancer when treatment has the best chance of a desired outcome. Awareness advertisements to bring attention to screening recommendations and annual consultation with a provider increase the likelihood of catching cancer early. Screening at suggested intervals and awareness of early cancer signs is the focus. These recommendations are reviewed frequently and new guidelines made available. Providers may choose which recommendations to follow when suggesting screening tests.
Some screenings are performed annually, such as mammograms and colonoscopies, even in those with no risk factors other than that of the corresponding population (biological sex, ethnicity, economic demographic, age). Testicular cancer screening is done by a provider at each annual screening, and individuals with testicles are advised to check monthly for lumps or changes. Skin cancer screening (in addition to self-surveillance) can also be done during the annual exam unless the patient has other risk factors.
Screening is also based on individual needs such as family history, lifestyle risk factors, and relevant medical society guidelines. For example, liver cancer screening is possible, but would only be done in conjunction with risk factors such as liver disease or hepatitis B or C infection. Lung cancer screening with low-dose CT scans is not routinely considered for individuals with no smoking or chemical exposure history. Colorectal cancer screening should be aggressive and early for individuals with a personal or familial history of Lynch syndrome.
Among medical society guidelines, there are different recommendations for cancer screenings. The organizations differ on the age to begin, age to cease screening, and length of intervals for screening; they conflict with each other in their published recommendations and supporting evidence. Organizations making recommendations vary by disease, but could include the American Cancer Society (ACS), World Health Organization (WHO), Centers for Disease Control and Prevention (CDC), United States Preventive Services Task Force (USPSTF), or the American College of Obstetricians and Gynecologists (ACOG).
Screening guidelines for common cancers are outlined in Table 31.2. It should be noted, however, that screening recommendations may differ by source and according to individual patient factors. Recommendations may be updated frequently. Ultimately, screenings to perform are chosen after a conversation between the clinician and the patient, accounting for variations between patients of average risk and those with individualized risk factors.
| Screening Test | Recommended Age/Frequency | Notes | |
|---|---|---|---|
| Breast cancer | Mammogram | Females ages 40–74: every two years (based on individual risk) | Females with high risk may require earlier or more frequent screenings. |
| Clinical breast exam (CBE) | Not routinely recommended for females with average risk. | Not recommended as part of routine screening. | |
| Cervical cancer | Pap smear (Pap test) | Females ages 21–29: every three years | Continue screening until age 65 with normal results. |
| HPV test | Females ages 30–65: every five years (alone or in combination with Pap) | Pap plus HPV testing every five years; HPV testing alone every five years. | |
| Colorectal cancer | Colonoscopy | Begin at age 45: every ten years | Alternatives include stool-based tests (e.g., FIT) or flexible sigmoidoscopy. Screening can be personalized based on patient risk factors. |
| Fecal immunochemical test (FIT) | Annually for individuals with average risk | Alternative to colonoscopy for those who prefer or have contraindications. | |
| Lung cancer | Low-dose CT scan | Adults ages 50–80 with a twenty pack-year smoking history: annually | Recommended for current or former smokers with a significant smoking history. Screening should be discontinued once a person has not smoked for fifteen years. |
| Prostate cancer | Prostate-specific antigen (PSA) test | Males ages 55–69: discuss with health-care provider | Screening decisions should be individualized, considering potential benefits and harms. Routine screening is not recommended for males under 55 or over 69. |
| Skin cancer | Visual skin examination | Regular self-exams and professional exams as needed | The USPSTF does not have a specific recommendation for routine skin exams; emphasis is on self-awareness and dermatologic evaluation if abnormalities are detected. |
Tertiary Prevention
The focus of tertiary prevention is reduction of symptoms and complications related to the disease process. This includes accessing the correct treatments, symptom management, emotional and social supports, and maintaining or regaining physical and emotional health after treatment has ended. Nurses assist patients in making behavior changes to improve their condition, planning their care to support their desired quality of life, and reinforcing or elaborating on decisions surrounding their care.