Helpful Information

About Serum Tumor Markers

Helpful Information about Serum Tumor Markers

Using non-invasive methods to detect early cancers, such as measuring tumor marker levels, is a commonly recognized method for cancer screening. With the exception of the prostate specific antigen (PSA), most tumor markers do not have sufficient sensitivity or specificity for use in early screening. Thus, using tumor markers alone often is not clinically useful and should be combined with other diagnostic modalities. However, they do have a crucial role for detecting disease and disease recurrence, and assessing response to tumor therapy in a selected group of patients.

Carcinoembryonic Antigen (CEA)

CEA is an onco-fetal glycoprotein expressed in normal mucosal cells and overly expressed in adenocarcinoma, especially colon cancer. Other cancers, such as lung cancer, breast cancer, and cervical cancer, may also cause increase in CEA. Non-neoplastic causes, including smoking, peptic ulcer disease, inflammatory bowel disease, cirrhosis, and biliary disease, may also be associated with elevated levels. In non-smokers, CEA should be < 5 ng/ml; if CEA is ≧10 ng/ml, one would be advised to rule out malignant cause. Because CEA cannot pinpoint tumor location or differentiate between benign and malignant diseases, it should be combined with other screening modalities, like colonoscopy. Its primary usage is to follow patients with recurrent colon cancer.

Alpha-fetoprotein (AFP)

AFP is a glycoprotein in fetal serum and drops to undetectable levels after birth. Normal AFP levels are usually <20 ng/ml and levels <200 ng/ml are often due to non-malignant causes. Primary malignancies associated with AFP elevation are hepatocellular carcinoma (HCC) and non-seminomatous germ cell tumors. Other gastrointestinal cancers, including gastric, colon, and pancreatic cancers, may cause increased levels. Non-neoplastic causes include acute, chronic hepatitis B and C, liver cirrhosis, pregnancy, and neuroblastoma.

AFP levels are abnormal in 60-80% of patients with HCC, often exceeding 1,000 ng/ml in 40% of these patients. AFP alone is not very useful for screening purposes and should be combined with an abdominal sonogram and liver function test for patients of high risks (hepatitis B chronic carriers, cirrhosis patients, chronic hepatitis B and/or C patients). if >1000ng/ml should rule out HCC.

Prostate-specific Antigen (PSA)

PSA is a glycoprotein produced by prostate epithelium. Normal serum levels are between 3.5-4.0 ng/ml. While PSA levels may normally increase with age, elevated levels may be due to prostate cancer, prostatitis, benign prostatic hypertrophy, prostatic trauma, and bladder infection. Since Taiwan’s national prostate cancer prevalence rate is generally lower, its predictive value may be lower. As such, PSA should not be the only screening tool, but should be combined with a digital exam.

Cancer Antigen 125 (CA-125)

CA-125 is a glycoprotein that lines the ovaries and is expressed by coelomic epithelium during fetal development. Elevation of CA-125 is associated with ovarian cancer, uterine cancer, and endometrial cancer. Many benign disorders, such as endometriosis, pelvic inflammatory disease, ovarian cyst, myoma, adenomyosis, and other non-gynecological causes (e.g. pancreatitis, cancer, liver cancer, hepatitis), may also be associated with elevated levels.

Due to low sensitivity and low disease prevalence, CA-125 is not very useful in early cancer screening and therefore has low positive prediction value. In post-menopausal women with a pelvic mass, if CA-125 >65µ/ml, its positive predictive value can reach 90-98% for ovarian cancer. In pre-menopausal women, CA-125 is less useful. This test should be combined with other exam methods for better screening value.

About Intravenous Anesthetics

Helpful Information about Intravenous Anesthetics

Gastroscopy (including esophagoscopy and duodenoscopy) and full-length colonoscopy are important for detecting problems of the upper and lower gastrointestinal tract. These procedures may cause nausea, stomachache, abdominal pain, and/or an intestinal bloating sensation. Light sedation and analgesia with intravenous anesthetics are often used during these procedures to lessen patient apprehension and discomfort. At our hospital, we are mindful of patient comfort and offer this service to those interested.

Before the procedure is performed, an intravenous line will be established. Benzodiazepine and narcotics will be administered for conscious sedation and analgesia during the procedure. If you are older than 75 years of age and/or have major systemic diseases (e.g. coronary artery disease, hypertension, diabetes, asthma), you may need a special anesthesiology consultation. If only sigmoidorectoscopy is performed, sedation is unnecessary in most cases.

After sedation and the endoscopic examination, you must rest in bed for about 30 minutes. Drinking, driving, and operating machinery on the same day are prohibited. You are advised not to make major decisions or attend important meetings until the next day. For safety, it is best to have an adult available to accompany you home.

In very rare instances (1/10,000 patients), complications may arise, such as an allergic reaction to the anesthetics or a major cardiopulmonary catastrophe. Should this happen, we are prepared to and will start the mandatory resuscitation procedure with standardized technology and equipment. While this sedation and analgesia is relatively safe, please be aware of and understand the associated risks before agreeing to the examination.

About the Nasopharyngeal Examination

Helpful Information about the Nasopharyngeal Examination

Nasopharyngeal cancer (NPC) occurs more frequently in individuals with ethnic Chinese background. The incidence rate is approximately 7.7/100,000/year for males, who are three times more likely to develop NPC than females. Doctors cannot directly examine the nasopharynx because this area is located in the back of the nasal cavity (about 10cm behind the nostrils). As such, ENT specialists may utilize one of the following two methods to perform the nasopharyngeal examination.

1. Routine reflex mirror (posterior rhinoscopic mirror exam): This small, round mirror is inserted through the mouth and provides a reflected image of the nasopharynx.

Advantage: Quick and simple. No other instruments are needed.

Disadvantage: It is difficult to get a clear view if you exhibit vomiting reflex and/or have a narrow, constricted throat.

2. Nasopharyngeal fiberoptic endoscopy examination: After local anesthesia is applied to the nasal cavity, the fiberscope is passed through the nose into the nasopharynx to check for any suspected lesions.

Advantage: Any minor lesion can be clearly viewed with this procedure. High-resolution photo images can also be taken.

Disadvantage: Takes longer (5-10 minutes) and is more expensive (~NT$1600).

We recommend the fiberoptic endoscopy examination for any patients with a prolonged nasal problem, family history of NPC, and/or an obscure nasopharyngeal lesion viewed with the routine reflex mirror.

About the ThinPrep Pap Test

Helpful Information about the ThinPrep Pap Test

The ThinPrep Pap test, a liquid-based test, was developed as a more comprehensive alternative to the traditional Pap smear. Studies have shown that the ThinPrep Pap test provides more accurate and reliable results. For the ThinPrep Pap test, the cervical cells are collected in the same manner as before, without any additional discomfort. However, instead of smearing the cells onto a glass slide, the doctor rinses the cells into a vial filled with a preservative solution. This procedure better preserves the sample and allows analysis of virtually all the cells.

About the HPV DNA Test

Helpful Information about the Human Papillomavirus (HPV) DNA Test for Cervical Cancer Screening

Studies show that nearly 90% of all squamous cell cervical carcinoma are related to infection by human papillomovirus (HPV), a small DNA virus. About 80 types are known to affect humans, with 22 of these more commonly associated with pelvic and genital infections. These types are further classified into 3 major classes based on their oncogenic risk, from low to high. In clinical studies, those who tested positive for a high-risk type of HPV infection often have a 70% risk for abnormal Pap smears in 2 years.

Currently, HPV DNA testing is done for 3 conditions:

Use in combination with screening cytologic tests (Pap smear) can decrease false negative rates and increase the sensitivity of the Pap smear. Based on the American Cancer Society’s guidelines, HPV screening is recommended for high-risk women over the age of 30, no more frequent than every 3 years.
In those with equivocal or slightly abnormal Pap smear results, the HPV DNA test can help determine a pre-cancerous lesion.
Use can assist in pre-treatment and follow-up in CIS lesions and squamous cell cervical carcinoma.

HPV DNA testing is a powerful tool for early cancer detection. It can be a very helpful supplement to routine Pap smears for patients with such risk factors as: early age of onset of sexual activity (<20 years old), multiple sexual partners, family history of cervical cancer, smoker, history of sexually transmitted diseases, multiple pregnancies and abortions, and other immunosuppressive diseases (HIV, chronic steroid use). If any of these risk factors apply to you, you may consider getting tested.