A new software platform has been developed by researchers from the USA and Germany to help in the diagnosis and treatment of breast cancer. The platform uses computational clinical imaging techniques and the mathematical concept of fractals for analysis and presentation of magnetic resonance imaging (MRI) scans and has shown potential in the early diagnosis of breast cancer
Early detection is considered the most effective tool in fighting breast cancer. Screening can detect small lumps in the breast up to 2 years before they become clinically apparent. Conventional mammography gives 2D views and has a sensitivity of 80–85%. Undetected tumors will enlarge and become more lethal before they are identified, either in later screening or when felt in a physical exam. Breast MRI is a relatively new tool that can be used as an adjunct to traditional breast mammography. It has the advantage of being able to provide 3D views of the breast and an accuracy approaching 100% for the detection of invasive cancer. Use of MRI for breast scans is not widespread, but the number of centers providing the scans is growing.
A study published recently in The American Journal of Radiology investigated suspected breast cancer using MRI. The authors found additional tumors in the same breast in over 30% and in the opposite breast in almost 10% of patients. These were tumors that were not detected by mammography or ultrasound. These led to changes in treatment for approximately 25% of newly diagnosed patients undergoing surgery. MRI-guided biopsies were also conducted and gave definitive answers.
Integration of this imaging technique and software into general imaging departments should improve care, reduce costs for unnecessary surgery and, ultimately, yield improved patient survival. These tools, and others, are continually being developed and evaluated for their clinical potential. While traditional mammography has undoubtedly helped many breast cancer patients, there remains the 15–20% of undetected tumors to be improved upon.
New imaging techniques for breast cancer scans, such as MRI, aid early diagnosis and management of breast cancer and thus improve overall patient care and survival.
New diagnostic tool for prostate cancer patients
A recently published study provides a new test for prognostic information for possible prostate cancer patients. The data show that whole-genome analysis, together with the standard biopsy, may give a more accurate diagnosis for men with suspected prostate cancer, reducing the number of misdiagnoses and optimizing therapeutic decisions.
Prostate cancer is particularly associated with western lifestyle and mainly affects men over the age of 65 years and rarely those under the age of 40 years. Statistics from the WHO show that there are approximately 250,000 new cases of prostate cancer. The disease has a high cure rate of 90% when detected early. However, the issue of misdiagnosis with current procedures is an important one and new methods of disease testing are needed.
At present, levels of prostate-specific antigen (PSA), a protein produced by the healthy prostate and cancer cells, are measured initially. High levels of PSA indicate an increased risk of cancer and, if detected, an ultrasound-guided sextant prostate biopsy is taken and analyzed histologically. If a carcinoma is detected in the sample then radical prostatectomy followed by radiotherapy is indicated. However, as biopsy samples are small, it is difficult to determine the tumor stage and grade reliably.
Comparative studies between diagnosed-from-biopsy samples and prostates postsurgery have concluded that biopsy analysis down- or overgrades approximately 57 and 20% of tumors, respectively. PSA analysis can also create problems as it may detect slow-growing tumors that may never cause problems to the patient.
Combined efforts from Portuguese and Norwegian groups have shown that it is possible to conduct whole-genome analysis from biopsy samples. These, together with the microscopic analysis, yield a more accurate prognosis and tumor classification.
In the study, 61 patients who had high PSA levels and histological evidence of prostate cancer were investigated. A control group of healthy individuals were also analyzed. Results showed that the total number of genomic aberrations in a patient’s prostate cells is correlated with disease severity. The control group showed no genomic changes in their prostate cells. Specifically, patients whose tumors displayed 8q gains had significantly worse survival, even when tumor grade was taken into account (p = 0.008). This was also the case when the analysis was limited to aggressive tumors with a Gleason score of 7 only, which are known to be difficult to give an accurate prognosis.
The authors hope that whole-genome analysis combined with microscopic analysis of biopsy samples will provide more accurate prognostic information, allowing more informed decisions regarding the treatment course to follow. This would allow doctors to closely monitor tumors, rather than advocating for radical prostectomy in all cases.
Fighting tumors with bubbles
Researchers from the University of Michigan (MI, USA) are developing a new technique in embolotherapy to block the blood flow to tumors using gas bubbles. This would allow doctors to precisely control where bubbles are formed, thus limiting the damage to neighboring tissue which could potentially be a useful technique in the treatment of many cancers, such as renal and liver cancer.
Embolotherapy traditionally uses solid emboli (blood-blocking ‘corks’), for example a gel or clot. However, a major difficulty encountered is that of restricting the emboli to the target tumor and minimizing the destruction of the surrounding tissue. This is usually achieved through insertion of a catheter into the body at the tumor site, an extremely invasive procedure. By using gas bubbles, this drawback can be avoided, as bubble formation can be controlled from outside the body using high-intensity focused ultrasound (HIFU).
Prior to the translation of this technique into the clinic, researchers must first understand the fundamental vaporization and transport topics involved, which are the subject of current investigation. At present, the technique is envisaged as a two-step process. Step one involves the intravenous injection of encapsulated superheated perfluorocarbon liquid droplets into the body. These droplets are small enough to pass through vessels without causing a blockage and can be imaged using ultrasound. Once they have reached their target destination (the tumor), HIFU is used to ‘pop’ the droplet. This causes the perfluorocarbon drop to expand into a gas bubble approximately 125-times the size of the droplet. The resulting bubble is larger than the vessel in diameter (if it remains spherical) and therefore elongates and lodges in the vessel. It is expected that with one or two doses of bubbles, most of the blood flow to the tumor will be blocked and without blood flow, the tumor will die.
Considerations that must be taken into account involve ensuring that the correct vessel is occluded and assessing the flexibility of the target vessel. However, this method could be particularly useful for treating cancers with high morbidity, such as hepatocellular cancer. Here, liver cirrhosis often creates difficulties for the conventional treatment of tumor removal, as so much of the liver is already damaged. An alternative treatment option, such as embolotherapy, would be of great benefit to these patients.
Ovarian cancer stem cells
In a report published recently in the Proceedings of the National Academy of Sciences (USA), researchers from Massachusetts General Hospital (MA, USA) have identified potential ovarian cancer stem cells. These may be the cause of the difficulty in treating ovarian cancer and further understanding their biology will hopefully allow the development of new treatment approaches for this often fatal disease.
Ovarian cancer is the fifth most common cause of cancer death and is responsible for the deaths of more than 16,000 women in the USA each year. Routine treatment of ovarian cancer entails surgical removal of all tissues involved followed by chemotherapy. Usually this treatment appears successful, but most patients experience treatment-resistant recurrences, the result of which is a 5-year survival rate of less than 30%.
Recent studies in leukemia and breast cancer have identified small populations of tumor cells that appear to act in a similar way to stem cells and drive tumors’ growth and spread. When these cells are not destroyed by chemo- or radiation therapy, tumors can recur and spread quickly, often in a treatment-resistant manner. Similar cancer stem cell lines have also been identified in CNS and gastrointestinal tumors.
Two mouse ovarian cancer cell lines were investigated and cells with similar characteristics to the cancer stem cell lines found with other tumors were identified. A comparison was made between subcutaneous injection of these stem cell-like cells and regular tumor cells. New tumors were formed faster in the mice injected with the cancer stem cells than the regular tumor cells. A small percentage of stem cell-like cells were also observed in human ovarian cancer cell lines and in cells taken from ascites that had accumulated in the abdomen of several ovarian cancer patients.
The potential ovarian cancer stem cells were more resistant to chemotherapy with doxorubicin than normal tumors, but remained sensitive to repeated treatment with the protein Mullerian inhibiting substance. This protein is important in the normal development of sexual organs and has been studied previously as a potential therapeutic option for reproductive tumors. The authors suggest that, as this protein appears to retain its efficacy against the stem cell-like cancer cells, it may prove important in the treatment of ovarian cancer. Other novel therapies and chemotherapeutic strategies targeted at these stem cell-like cells will also be investigated.