A small green sponge discovered in dark, icy waters of the Pacific off Alaska could be the first effective weapon against pancreatic cancer, researchers said Wednesday.
Pancreatic cancer, with particularly aggressive tumors, is notoriously difficult to treat.
A small green sponge, photographed by an ROV camera, seen in the waters off the coast of Alaska. (AFP / MANILA BULLETIN)
“One would never have imagined looking at this sponge that it could be miraculous,” Bob Stone, a researcher at the NOAA Alaska Fisheries Science Center, said in a briefing by phone.
Stone discovered the sponge, dull in color, called “Latrunculia austini” in 2005 while on a seabed exploration expedition in Alaska.
It lives on rocks in patches at depths of 230-720 feet (70-219m).
Lab testing has shown that several molecules in this sponge selectively destroy pancreatic cancer cells, said Mark Hamann, a University of South Carolina researcher working with Fred Valeriote of the Henry Ford Cancer Institute in Detroit.
“This is undoubtedly the most active molecule against pancreatic cancer that we see,” said Hamann. “Although there is still much work to be done, it marks the first key step in the discovery and process of developing a treatment,” he said.
Pancreatic cancer progresses slowly, a circumstance which leaves patients in a tough position as late diagnosis means little chance for successful treatment.
Patients’ chances of survival at five years for this tumor are only 14%, according to the American Cancer Society.
“I’ve looked at 5,000 sponge extracts over the last two decades,” Valeriote said. “In terms of this particular pattern of pancreatic and ovarian cancer selective activity, we’ve only seen one (other) sponge with such activity, and that was one collected many years ago in Indonesia.”
In the United States, 53,670 new cases of pancreatic cancer will be diagnosed in 2017 and more than 43,000 people will die.
British disease experts on Thursday suggested doing away with the “incorrect” advice to always finish a course of antibiotics, saying the approach was fueling the spread of drug resistance.
Rather than stopping antibiotics too early, the cause of resistance was “unnecessary” drug use, a team wrote in The BMJ medical journal.
(AFP / MANILA BULLETIN)
“We encourage policy makers, educators and doctors to stop advocating ‘complete the course’ when communicating with the public,” wrote the team, led by infectious diseases expert Martin Llewelyn of the Brighton and Sussex Medical School.
“Further, they should publicly and actively state that this was not evidence-based and is incorrect.”
The team said further research is needed to work out the best alternative guidelines, but “patients might be best advised to stop treatment when they feel better.”
The UN’s World Health Organization says that if treatment is stopped early, there is a risk that antibiotics would not have killed all the disease-causing bacteria, which can mutate and become resistant to the treatment.
It advises patients to “take the full prescription” given by their doctor.
The US Food and Drug Administration, too, advises taking “the full course of the drug”.
But the new paper, which analysed established links between treatment duration and effectiveness, and drug resistance, said there was no evidence for the idea that shorter treatment is inferior, or will trigger antibiotic resistance.
“When a patient takes antibiotics for any reason, antibiotic sensitive species and strains among (microorganisms) on their skin or gut or in the environment are replaced by resistant species and strains ready to cause infection in the future,” the team explained.
The longer the antibiotic exposure, the bigger the foothold resistant species will gain. These resistant strains can be transmitted directly between people who have no symptoms of illness.
Yet the idea of completing an antibiotics course is “deeply embedded” in both doctors and patients, said the team.
Experts not involved in the analysis welcomed its conclusions.
Prescriptions ‘need to change’
In comments via the Science Media Centre in London, Peter Openshaw, president of the British Society for Immunology, agreed that shortening antibiotics courses may help tackle the resistance problem.
“It could be that antibiotics should be used only to reduce the bacterial burden to a level that can be coped with by the person’s own immune system,” he said.
There are, however, cases which call for extended treatment courses — when a patient has a compromised immune system, for example, or if the bacteria is a slow-growing kind or can lie dormant before striking, such as tuberculosis.
“It is very clear that prescribing practices do need to change,” added Mark Woolhouse, a professor of epidemiology at the University of Edinburgh.
“Current volumes of antibiotic usage are too high to be sustainable.”
At more than P5,000, Zostavax, the only herpes zoster vaccine currently available, is indeed rather expensive, but is it worth its price? I think this is a question which you yourself should answer, but I’ll help you decide by telling you what you need to know about the disease and its vaccine.
Herpes zoster or shingles (“kulebra,” in Filipino) is a peculiar disease. It is caused by the varicella-zoster virus (VZV), the same microorganism that causes chickenpox, but its manifestations are very different from the latter. Also, only people who previously had a natural infection with chickenpox or had been immunized with the chickenpox vaccine can develop the disease.
Primary infection with VZV results in chickenpox, which generally resolves spontaneously, but the virus does not perish, it simply hides in nervous tissues where it stays dormant for a long time. Presumably, this is also what the virus does when given in attenuated form as a vaccine. Years or decades later, the virus may break out and give rise, not to chickenpox, but to herpes zoster. Exactly how VZV remains latent, subsequently re-activate, and cause another disease is not understood.
Shingles can occur in young people, but a person’s risk for the disease and its complications increases with age. Statistics show that one out of every three people 60 years old or older will get shingles. Of these, one out of six will experience PHN.
Most people have only one episode of herpes zoster in their lifetime. Second and even third episodes, however, are possible.
Shingles is a painful ailment
Shingles is characterized by painful skin blisters or rashes that usually develop in a limited area on one side of the body, extremities, or face. The skin lesions are typically preceded by one to two days of pain over the involved skin area. The pain persists and often intensifies after the skin lesions appear.
The virus also affects the nerves that supply the area of the skin where the lesions are located. Thus, if the skin lesions are around the anal or bladder area, the patient may experience bladder and bowel problems. Likewise, it is not unusual for the patient to experience diminished sensation on the affected skin area or paralysis of the muscles that are supplied by the involved nerve. Also, lesions around the eye may cause impairment of vision.
The signs and symptoms of shingles generally subside within two to four weeks, but some people experience residual nerve pain, which can be very severe and debilitating, for months or years, a condition called postherpetic neuralgia (PHN). Rarely, the sensory loss, paralysis, and visual problems become permanent, too.
Shingles may have other long term complications
South Korean researchers who recently examined a database of 519,880 patients have noted another possible long-term health risk of shingles. They found out that people who had shingles had an overall 41 percent higher risk of cardiovascular events, such as heart attack or stroke, when compared to an age-matched control group that did not develop shingles. The risk of stroke was 35 percent higher and heart attack 59 percent higher.
The management of herpes zoster is difficult and expensive
There is no cure for herpes zoster. A variety of analgesics, to relieve the pain, are the main drugs prescribed by physicians. There are several antiviral agents—acyclovir, famciclovir, and valacyclovir—that can reduce the pain and shorten the duration of herpes zoster, but they are effective only if given early in the disease. For PHN, anti-depressants such as amitriptyline, anticonvulsants like gabapentin, and opioids such as codeine are used, but results are inconsistent. Overall, the treatment of herpes shingles and its complications is decidedly more expensive than the vaccine.
Does the herpes zoster vaccine offer full protection?
Zostavax, the herpes zoster vaccine, which is recommended for people aged 60 years and older and administered as a single shot, is not 100 percent effective. It merely reduces the risk of developing shingles by only 51 percent and PHN by 67 percent. Also, its efficacy wanes within the first five years after vaccination, and protection beyond five years is uncertain.