All of these may be factors in the diagnosis of cancer. The operative word in the question is ‘risk.’ Common risk factors for breast cancer include previous immunosuppression, advancing age, and genetic predisposition. Common causative factors include smoking, alcohol use, radiation,  chronic irritation, consumption of food additives, exposure to industrial chemicals such as asbestos, exposure to dangerous pharmaceuticals such as stillbesterol, previous viral infection such as Epstein-Barr, and stress (when combined with other causative factors).

The correct answer is "Cancer antigen (CA-125)" because CA-125, also known as mucin 16, is a glycoprotein that is found to have elevated serum levels in patients with a variety of cancers (including ovarian cancer) and benign conditions, as compared to patients without such conditions. As a result, monitoring CA-125 levels can be used as a method of tracking disease progression or response to treatment based upon what the initial CA-125 level is at the time of diagnosis. 

On the other hand, the other choices are incorrect. Cancer antigen 19-9 (CA 19-9) is incorrect as this is a biomarker in pancreatic cancer, not ovarian cancer.Prostate specific antigen (PSA) is incorrect as this is a biomarker in prostate cancer (and other prostate conditions), not ovarian cancer. c-KIT is incorrect as this is a biomarker in gastrointestinal stromal tumors, not ovarian cancer. BCR/ABL is incorrect as this is the translocation found in the Philadelphia Chromosome implicated in chronic myelogenous leukemia, not ovarian cancer.

The correct answer is "Cancer antigen 19-9 (CA 19-9)" because CA 19-9 is often elevated in patients who have pancreatic cancer (or certain types of colon cancers), and can be used to assess response to treatment and/or disease progression. 

On the other hand, the other choices are incorrect. Cancer antigen-125 (CA-125) is incorrect as this is a tumor marker used to track ovarian cancer, not pancreatic cancer. CD20 antigen is a tumor marker for B-cell lymphomas and leukemias, not pancreatic cancer. CD30 antigen is a tumor marker for anaplastic large cell lymphoma, not pancreatic cancer. BRAF is a tumor marker for melanoma, not pancreatic cancer.

A CT scan is the preferred imaging modality to view a tumor in the lung tissue. A chest x-ray might initially find a nodule or abnormal marking in the lungs, but it must be followed up with a CT scan to be diagnostic. EKG looks at the heart and EEG looks at the brain. 

The correct answer is "rectal bleeding." This answer is correct, as the patient is being treated with chemotherapy and radiation therapy for anal cancer, and is multiple weeks removed from treatment. Rectal bleeding is a very common side effect in patients who recently received radiation therapy to the anus, as numerous blood vessels are treated by the radiation therapy, and the body's immunologic response to radiation therapy also promotes vascular permeability. Rectal bleeding, unless profuse and uncontrolled is often a self-limiting phenomenon in the setting of radiation and while troublesome for the patient, does not pose much of an acute threat to the patient's stability.

Fever is something that should be taken seriously in any cancer patient, especially one receiving chemotherapy. However, it should not necessarily be expected. It should always be assessed for.

Headache is a common side effect in patients actively receiving chemotherapy, often either directly due to the chemotherapy drug itself, or to dehydration as a side effect of treatment/lack of appetite. This patient is multiple weeks removed from chemotherapy though, so headache would not be expected as a treatment side effect at this time.

Pupil dilation and eye redness are not typical side effects of chemotherapy or radiation therapy for anal cancer.

The correct answer is "Vinblastine-induced neuropathy." 

This is the most likely explanation for this patient's peripheral neuropathy, as the patient is described as being healthy aside from Hodgkin's lymphoma, and on no medications aside from his chemotherapy regimen. As a result, diabetic neuropathy and selective serotonin reuptake inhibitor discontinuation syndrome can each be ruled out as etiologies. Similarly, given that he is otherwise healthy and not complaining of any additional neurological symptoms (and given that he is young and actively receiving chemotherapy) it is unlikely that he is experiencing posterior spinal cord degeneration. 

Thus, in a young patient with lymphoma who is receiving chemotherapy and experiencing peripheral neuropathy, the most likely etiology is one of the chemotherapy medications that he is receiving. In this patient's case, he is receiving doxorubicin, bleomycin, vinblastine, and dacarbazine. Of these medications, vinblastine is the most strongly associated with peripheral neuropathy, as this is a fairly common side effect of vinblastine and other agents in the same class (vinca alkaloids). As such, vinblastine-induced neuropathy is the most likely etiology.

The correct answer is "PET-CT." This is the correct answer because a PET-CT shows not only spatial information from the serial slices taken on CT imaging, which would include the size and location of any potential tumor, scarring, or nodal involvement, but also the FDG-avidity or uptake of the contents of the image, which would help correlate the spatial findings with possible disease activity. Nodules observed on a CT scan can be non-descript, ranging from malignant, to indeterminate, to benign (which may still be infectious or inflammatory). The addition of PET to a CT allows the observer to see which nodules, nodes, or lesions are more likely to be indicative of disease burden, as tumors and infections will have greater FDG uptake since they are more metabolically active than surrounding tissues. 

MRI is not typically used to assess treatment in lung cancer as CT coupled with PET is more commonly used. X-ray does not provide enough resolution to adequately assess response to cancer treatment. Pulmonary function tests, while a useful measure of lung functionality, do not give a specific picture of the lung cancer burden and as such are not the best treatment response assessment tool.

The correct answer is "MRI Head." This is the correct answer because in evaluating brain parenchyma, which is relatively soft tissue, MRI provides the greatest degree of spatial resolution, which would best allow assessment of any residual, recurrent, or new tumor burden within the brain. CT imaging is commonly used to assess the brain when evaluating for bleeds or fractures, among other conditions, as it is far more expedient than MRI. However, it does not visualize the soft tissue of the brain parenchyma as well as MRI, and treatment response MRI scans are often not emergent, and therefore MRI would be preferred. PET-CT, while often highly useful in oncologic assessments is of limited value in evaluating the brain for cancer response, because the entire brain is highly metabolically active in nearly all patients, and therefore the entire brain typically has a great deal of FDG uptake uniformly, limiting the value of the scan.

The priority for this client is to ensure a patent airway by placing him the Fowler's or semi upright seated position. Giving oxygen is warranted but will be given after the client is positioned correctly. ABG's would be helpful in this situation but it not the priority. Auscultation of breath sounds and assessment of mental status are not indicated.

The final stage of a pertussis infection is known as the convalescent phase. This occurs for 2-6 weeks, after the paroxysmal stage of the disease. During this time coughing decreases, and paroxysms are less severe. The infected individual may experience increased susceptibility to upper and lower respiratory conditions for as much as 6 months after resolution of the infection.