What is a sentinel lymph node?

www.breastcancer.org explains it well:

The dictionary defines "sentinel" as a guard, watchdog, or protector. Likewise, the sentinel lymph node is the first node "standing guard" for your breast. In sentinel lymph node dissection, the surgeon looks for the very first lymph node that filters fluid draining away from the area of the breast that contained the breast cancer. If cancer cells are breaking away from the tumor and traveling away from your breast via the lymph system, the sentinel lymph node is more likely than other lymph nodes to contain cancer.

When I was diagnosed with breast cancer my head was spinning when my surgeon offered me to participate in a clinical trial. The trial would put women in two groups. One would have just the sentinel node removal and the other group would have a full axillary dissection.

Touch imprint cytology (TIC) lymph node assessment during breast cancer surgery could prove to have advantages over the current standard lymph node assessment. TIC can be important to the breast cancer patient because usually the results from the lymph node dissection can take up to a week. It causes a lot of anxiety and stress waiting to find out if the breast cancer has metastasized to the lymph nodes. TIC would provide immediate results during the sentinel node extraction.

An economic assessment that was published in the November 15, 2006 issue of Cancer says TIC is less costly than standard lymph node assessment. They studied the cost effectiveness of the two techniques and found that especially in larger tumors TIC is more effective.

Just two months after her mother lost her battle with gall bladder cancer, Liane was diagnosed with breast cancer. It all happened earlier this year -- and while Liane is still mourning the loss of her mother, she is also still managing the madness of her own disease. Liane is surviving with courage, with determination, with the same powerful spirit that powered her mother's fight.

Liane lives in a small city -- population 43,000 -- in northern Alberta Canada. She has been happily married for 18 years and has two daughters, ages 13 and 15, and a golden retriever named Sunny. Liane loves to garden, cook, read, and spend time with family. She normally works full-time in a real estate and property management office but has been blessed with six months off for treatment. Liane is already -- without a doubt -- a survivor.

Melanoma patients that have a intermediate-thickness, 1.2mm - 3.5mm size tumor, should receive a lymph node dissection and sentinel biopsy at the same time the tumor is removed.

The results of a clinical trial showed that survival was significantly improved in patients that had the nodes removed at initial surgery than those that waited and had lymph node enlargement appear later. Melanoma tumors in the lymph nodes are important to find before they become clinically detectable. The lymph node staging process can help determine the treatment that is needed.

The clinical trial called Multicenter Selective Lymphadenectomy Trial (MSLT) reported the interim results to the New England Journal of Medicine. Patients were put into two groups for the clinical trial. The first group with intermediate-thickness melanoma was given a wide excision and sentinel node biopsy and the second group was given a wide excision and nodal observation. The group with the sentinel node biopsy ended up having smaller metastasis in the nodes than those that only were observed. It showed that those who waited for clinical enlargement of lymph nodes to have them removed and analyzed had further disease progression in the nodes and lesser survival rates.

Dr. Balch, from Johns Hopkins Medical Institutions in Baltimore, and Dr. Cascinelli, from the National Tumor Institute in Milan say that the results of the trial "convincingly show that sentinel node biopsy is a standard of care staging procedure and is justified in patients with melanoma with tumor thickness of 1.2 to 3.5 mm"

Gastric cancer staging by lymph node sampling has a profound effect on patient survival. Survival of patients with gastric cancer can be compromised if the staging is done inadequately. This can happen if too few lymph nodes are removed and analyzed.

A study in an issue of Cancer, a peer-review journal of the American Cancer Society revealed that less than one third of gastric cancer patients had adequate lymph node assessments (ALNA). There was a change in the guidelines of the staging system for gastric cancer in 1997 but since then only minimal improvements have been made.

Compliance with the new guidelines remains poor because the lymph nodes removed and sampled since the change in the guidelines only increased from 9 nodes to 10. The guidelines now say that 15 lymph nodes removed and analyzed should be the standard. The lymph nodes that are tested will show how far the cancer has spread. If you do not have the correct information that the lymph node sampling can provide it can cause the patient to receive incorrect treatments and less survival rates.

Researchers in Spain conducted a study among 1606 women with node-negative breast cancer. The results were published in the Annals of Oncology. What the researchers wanted to find out is whether the number of lymph nodes removed during axillary lymph node dissection influences risk of recurrence. Axillary lymph node sampling is a necessary procedure to stage a patient diagnosed with breast cancer. Women who underwent sentinel lymph node biopsy were not included in the study.

The researchers discovered that there was an increased risk of local breast cancer recurrence if fewer than six lymph nodes were removed. If the surgeon removes less than six lymph nodes there is a risk that other lymph nodes that could contain cancer can be missed. This can result in under staging and the patient not receiving the correct treatment plan.

In order to be confident that the patient does indeed have node negative breast cancer it is important to remove at least six lymph nodes for evaluation.

Positron emission tomography (PET) can measure metabolic activity of tissue. Cancer cells tend to have a higher metabolism than normal tissue, which can be determined on PET for more accurate detection of cancer.

Using the PET scan after diagnoses of breast cancer to check lymph nodes for cancer was looked at in a study that was published in the Archives of Surgery. What the study found out is that the PET scan can detect 60 percent of patients with positive nodes. These patients that know they have positive nodes might be able to start therapy and avoid the axillary dissection or the sentinel node biopsy. These surgical procedures can often have side effects. By avoiding these surgeries a patient that knows they have positive lymph nodes won't have to wait for surgery and extra time to heal to start chemotherapy or other treatments.

If a patient has a negative PET scan showing no cancer in the lymph nodes the axillary dissection or the sentinel node biopsy should be performed since the PET can only pick up 60 percent of patients cancer in the lymph nodes. The patients could still have microscopic cancer cells that the PET can't pick up so in this case surgery is needed.

Getting accurate information on whether or not the cancer was confined to the breast has a big impact on the treatment plan.