Advances in fluorescent probe technology could allow real-time visualization of cancer progression during surgery

June 4, 2014
The metastasized lymph node (top) of a mouse injected with the probe shows lower fluorescence signal intensity than a normal lymph node (bottom). Credit: Jung Sun Yoo, National University of Singapore

In order to determine the best treatment for patients affected by cancer, it is crucial for physicians to identify how the disease is spreading via lymph nodes in the body—a process known as metastasis. Progression of the disease is currently monitored by dissecting lymph nodes during surgery and subsequently performing biopsies. However, using a more sensitive and accurate method that is less invasive based on optical imaging technologies to visualize disease progression in situ could further improve cancer patient diagnoses and limit the time that they are required to spend in surgery.

Now, Young-Tae Chang and co-workers at the A*STAR Singapore Bioimaging Consortium, together with Jung Sun Yoo and researchers at the National University of Singapore, have developed a novel that is capable of infiltrating lymph nodes and highlighting cancer progression. The probe could potentially be used to provide information for making rapid diagnoses during surgery.

"Immune cells in lymph nodes, such as macrophages, have a novel role in ," explains Yoo. "We wanted to find a macrophage-targeting fluorescent probe that could distinguish metastasized lymph nodes from inflamed or normal lymph nodes."

The team sifted through many libraries of fluorochromes—small nontoxic organic molecules suitable for intraoperative imaging—while searching for those that could specifically stain macrophages. Flow cytometry and testing with human blood samples allowed the researchers to select the best fit for their fluorescent probe.

"We then used the probe for in vivo mouse imaging," explains Yoo. "This tested whether the probe could pinpoint the sentinel lymph node—the first node to drain a tumor and potentially initiate cancer spreading through the body." Following injection, the team's probe immediately accumulated in the of the mouse, with bright signals in inflamed nodes and less bright signals in metastasized nodes (see image).

The new has several potential biomedical applications. Researchers could use it to investigate the behavior of macrophages in in vivo. Surgeons could obtain real-time information on the infiltration of tumors and how far the disease has spread while a patient is still in surgery, eliminating the need for pre-operative biopsies and minimizing the potential for further surgical procedures.

"We also hope to develop macrophage probes with near-infrared for better depth penetration, as well as subset-specific agents capable of differentiating between 'good' and 'bad' macrophages in many different diseases," states Yoo. "Subtype-specific fluorochromes will have a high impact on the future of clinical imaging."

Explore further: Lymph node ultrasounds more accurate in obese breast cancer patients

More information: Yoo, J. S., Lee, S.-C., Jow, Z. Y., Koh, P. Y. X. & Chang, Y.-T. "A macrophage-specific fluorescent probe for intraoperative lymph node staging." Cancer Research 74, 44–55 (2014). dx.doi.org/10.1158/0008-5472.CAN-13-2129

Related Stories

Lymph node ultrasounds more accurate in obese breast cancer patients

April 30, 2014
Mayo Clinic research into whether ultrasounds to detect breast cancer in underarm lymph nodes are less effective in obese women has produced a surprising finding. Fat didn't obscure the images—and ultrasounds showing no ...

Less invasive surgery detects residual breast cancer in lymph nodes after chemotherapy

December 5, 2012
Most patients whose breast cancer has spread to their lymph nodes have most of the lymph nodes in their armpit area removed after chemotherapy to see if any cancer remains. A study conducted through the American College of ...

Lymphoseek approved to help locate lymph nodes

March 13, 2013
(HealthDay)—The injected imaging drug Lymphoseek (technetium Tc 99m tilmanocept) has been approved by the U.S. Food and Drug Administration to help surgeons locate the lymph nodes among people with breast cancer or melanoma.

Study questions use of less-invasive lymph node surgery for breast cancer

October 7, 2013
(HealthDay)—A study that sought to see if a less-invasive, less-debilitating procedure could determine accurately how far breast cancer has spread fell short of the safety threshold the researchers set.

Immune profile of lymph nodes nearest to tumor may predict melanoma progression

January 6, 2014
(Medical Xpress)—Melanoma patients who had a specific subtype of immune cells called CD30-positive T cells in the lymph nodes closest to their tumors were more likely to have their disease progress within five years, according ...

New guidelines might limit need for lymph node removal for breast cancer

March 24, 2014
(HealthDay)—Biopsies of so-called "sentinel" lymph nodes under the arms should become more widespread among breast cancer patients, according to updated guidelines from the American Society of Clinical Oncology (ASCO).

Recommended for you

No dye: Cancer patients' gray hair darkened on immune drugs

July 21, 2017
Cancer patients' gray hair unexpectedly turned youthfully dark while taking novel drugs, and it has doctors scratching their heads.

Shooting the achilles heel of nervous system cancers

July 20, 2017
Virtually all cancer treatments used today also damage normal cells, causing the toxic side effects associated with cancer treatment. A cooperative research team led by researchers at Dartmouth's Norris Cotton Cancer Center ...

Molecular changes with age in normal breast tissue are linked to cancer-related changes

July 20, 2017
Several known factors are associated with a higher risk of breast cancer including increasing age, being overweight after menopause, alcohol intake, and family history. However, the underlying biologic mechanisms through ...

Immune-cell numbers predict response to combination immunotherapy in melanoma

July 20, 2017
Whether a melanoma patient will better respond to a single immunotherapy drug or two in combination depends on the abundance of certain white blood cells within their tumors, according to a new study conducted by UC San Francisco ...

Discovery could lead to better results for patients undergoing radiation

July 19, 2017
More than half of cancer patients undergo radiotherapy, in which high doses of radiation are aimed at diseased tissue to kill cancer cells. But due to a phenomenon known as radiation-induced bystander effect (RIBE), in which ...

Definitive genomic study reveals alterations driving most medulloblastoma brain tumors

July 19, 2017
The most comprehensive analysis yet of medulloblastoma has identified genomic changes responsible for more than 75 percent of the brain tumors, including two new suspected cancer genes that were found exclusively in the least ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.