Oncology Flashcards
Physical activity has been shown to decrease which type of cancer? (H20 C66 P444) A. Colon B. Leukemia C. Lung D. Prostate
The answer is A. Physical activity is associated with a decreased risk of colon and breast cancer. A variety of mechanisms have been proposed. However, such studies are prone to confounding factors such as recall bias, association of exercise with other health-related practices, and effects of preclinical cancers on exercise habits (reverse causality).
The accuracy of a diagnostic test determines its value in cancer screening. Which of the following describes the proportion of persons with a positive test who have the condition? (H20 C66 P447) A. Negative predictive value B. Positive predictive value C. Sensitivity D. Specificity
The answer is B.
Sensitivity is the proportion of persons with the condition who test positive: a /(a + c). Specificity is the proportion of persons without the condition who test negative: d /(b + d). Positive predictive value (PPV) is the proportion of persons with a positive test who have the condition: a /(a + b). Negative predictive value is he proportion of persons with a negative test who do not have the condition: d /(c + d).
Which of the following statements regarding screening for lung cancer in the National Lung Screening Trial using low-dose CT scanning is true? (H20 C66 P451)
A. Greater than 80% of positive results were found to be malignant after biopsy.
B. Positive results were found in approximately 5% of patients over the 3-year trial.
C. The trial compared the use of chest radiograph versus low-dose CT scan in patients 30–50 years old.
D. There was a reduction in lung cancer mortality in the low-dose CT group.
E. There was no difference in all-cause mortality between the CT and radiograph groups.
The answer is D. Chest x-ray and sputum cytology have been evaluated in several randomized lung cancer screening trials. The most recent and largest (n = 154,901) of these, a component of the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial, found that, compared with usual care, annual chest x-ray did not reduce the risk of dying from lung cancer (relative risk 0.99; 95% confidence interval 0.87–1.22) after 13 years. Low-dose CT has also been evaluated in several randomized trials. The largest and longest of these, the National Lung Screening Trial (NLST), was a randomized controlled trial of screening for lung cancer in ∼53,000 persons age 55–74 years with a 30+ pack-year smoking history. It demonstrated a statistically significant relative reduction of about 15–20% in lung cancer mortality in the CT arm compared to the chest x-ray arm (or about 3 fewer deaths per 1000 people screened with CT). However, the harms include the potential radiation risks associated with multiple scans, the discovery of incidental findings of unclear significance, and a high rate of false-positive test results. Both incidental findings and false-positive tests can lead to invasive diagnostic procedures associated with anxiety, expense, and complications (e.g., pneumo- or hemothorax after lung biopsy). The NLST was performed at experienced screening centers, and the balance of benefits and harms may differ in the community setting at less experienced centers.
What is the most common presentation of Hodgkin lymphoma? (H20 C105 P781) A. Night sweats B. Palpable lymphadenopathy C. Pel-Ebstein fever D. Weight loss
The answer is B. Most patients with cHL present with palpable lymphadenopathy that is nontender; in most patients, these lymph nodes are in the neck, supraclavicular area, and axilla. More than half of the patients will have mediastinal adenopathy at diagnosis, and this is sometimes the initial manifestation. Subdiaphragmatic presentation of cHL is unusual and more common in older males. One- third of patients present with fevers, night sweats, and/or weight loss, or “B” symptoms. Occasionally, HL can present as a fever of unknown origin. This is more common in older patients who are found to have mixed-cellularity HL in an abdominal site. Rarely, the fevers persist for days to weeks, followed by afebrile intervals and then recurrence of the fever. This pattern is known as Pel-Ebstein fever. HL can occasionally present with unusual manifestations. These include severe and unexplained itching, cutaneous disorders such as erythema nodosum and ichthyosiform atrophy, paraneoplastic cerebellar degeneration and other distant effects on the CNS, nephrotic syndrome, immune hemolytic anemia and thrombocytopenia, hypercalcemia, and pain in lymph nodes on alcohol ingestion.
A patient presents with progressive proximal muscle weakness, dry mouth, and weight loss. On testing, there was improvement of muscle strength after exercise. Knowing that this is related with a paraneoplastic process, what examination would you request for in this patient? (H20 C90 P669) A. Cranial magnetic resonance imaging B. Chest and abdominal CT scan C. Fundoscopy D. Transvaginal ultrasound
The answer is B. If symptoms involve peripheral nerve, neuromuscular junction, or muscle, the diagnosis of a specific PND is usually established on clinical, electrophysiologic, and pathologic grounds. The clinical history, accompanying symptoms (e.g., anorexia, weight loss), and type of syndrome dictate the studies and degree of effort needed to demonstrate a neoplasm. For example, the frequent association of Lambert-Eaton myasthenic syndrome (LEMS) with SCLC should lead to a chest and abdomen computed tomography (CT) or body positron emission tomography (PET) scan and, if negative, periodic tumor screening for at least 3 years after the neurologic diagnosis. In contrast, the weak association of polymyositis with cancer calls into question, the need for repeated cancer screenings in this situation. Serum and urine immunofixation studies should be considered in patients with peripheral neuropathy of unknown cause; detection of a monoclonal gammopathy suggests the need for additional studies to uncover a B cell or plasma cell malignancy. In paraneoplastic neuropathies, diagnostically useful antineuronal antibodies are limited to CRMP5 and Hu (ANNA1).
Which of the following lymphoid malignancies is associated with Epstein-Barr virus? (H20 C104 P771) A. Adult T-cell lymphoma B. Burkitt’s lymphoma C. Lymphoplasmacytic lymphoma D. Multicentric Castleman’s disease
The answer is B. Malignancies associated with Epstein-Barr virus are Burkitt’s lymphoma, post-organ transplant lymphoma, primary CNS diffuse large B-cell lymphoma, hodgkin’s lymphoma, and nasal-type extranodal NK/T-cell lymphoma. Adult T-cell lymphoma is associated with HTLV-1. Lymphoplasmacytic lymphoma is associated with hepatitis C virus. Multicentric Castleman’s disease, together with primary effusion lymphoma, is associated with human herpesvirus 8.
What is the single most powerful predictor of survival for patients with multiple myeloma? (H20 C107 P798-9) A. Serum alkaline phosphatase B. Serum β2-microglobulin C. Serum M protein levels D. Urinary light chain levels
The answer is B. Serum β2-microglobulin is the single most powerful predictor of survival and can substitute for staging. β2-Microglobulin is the light chain of the class I major histocompatibility antigens (HLA-A, -B, -C) on the surface of every cell. Combination of serum β2-microglobulin and albumin levels forms the basis for a three-stage International Staging System (ISS) (Table 107-3) that predicts survival. With the use of high- dose therapy and the newer agents, the Durie-Salmon staging system is unable to predict outcome and thus is no longer used. High labeling index, circulating plasma cells, performance status, and high levels of lactate dehydrogenase are also associated with poor prognosis.
