Innovations in Breast Cancer Diagnosis and Treatment

  • Posted on: Mon, 10/19/2015 - 17:24
  • By: OCHIS
Abstract:
What can breast cancer remind you? Only celebrities passed away with it? Breast cancer is terrible only when you don’t have enough knowledge about it. Modern medicine can cure and prevent breast cancer.

Breast cancer, by definition is malignant tumor happened in breast. More precisely, it is malignant tumor happened in breast ductal and lobules. It happens on females in most cases but also on males for about 1 out of 100 cases. It’s the most common malignant tumor in female worldwide. In China, 169,000 women are diagnosed with breast cancer each year, ranking the second most common cancer in woman. Morbidity is high in developed countries such as US and Europe, and increases in developing countries. Due to the wide application of breast cancer screening and early diagnosis in high morbidity countries, early diagnosis rate is increasing. Thanks to the efficient interference to the potential risk factors of breast cancer, and the development of screening and treatment, breast cancer modality is decreasing in recent years.

The cause of breast cancer

The cause of breast cancer is not known completely, but potentially includes the factors listed below.

  1. Family history and related gene Quite a few studies suggested that family history of breast cancer is an important risk factor. People with breast cancer family history have significant higher probability to have breast cancer compare to others. The risk is even higher in those whose closest families, such as parents, sibling and children, had breast cancer. Moreover, the risk is higher when more relatives had breast cancer, and the younger the age. This is Genetic inheritance related.

    Currently, it is believed that the gene mutation of BRCA1 and BRCA2 increases the risk of having breast cancer. For women who had positive results of gene mutation of BRCA1 and BRCA2, instead of be anxious and panic, should pay serious attention to it and do the screening more often and consult specialist. Angelina Julie is an example of choosing prophylactic mastectomy who has the mutation BRCA1 gene, and prophylactic mastectomy is not rare in the US.

  2. Reproductive factors Early age at menarche (earlier than 12 years old), late age of menopause (later than 55 years), short menstrual cycle, child-bearing age (having no children or late than 30-year-old), not breast-feeding or only few months breast-feeding and so on, will increase the likelihood of women developing breast cancer.

  3. Sex hormones Breast cancer is related to sex hormones, especially estrogen. Reproductive factors showed above is the main cause of endogenous estrogen exposure, however, exogenous estrogens, such as use hormone replacement therapy for long term, will also increase the risk of developing breast cancer. Besides, androgens, prolactin, serum insulin-like growth factor and its main binding protein are also considered to be related with the occurrence of breast cancer.

  4. Nutrition and diet High-calorie diet will accelerate the growth, advance early age of menarche, gain weight, eventually increase the incidence of breast cancer. Research has shown that drinking alcohol could also be a risk factor of developing breast cancer, which is correlated with its consumption. Compare to drinking alcohol, smoking has less influence on developing breast cancer, but still has weak influence, which is correlated with the amount and age. Passive smoking (breathing in environmental tobacco smoke, such as your husband’s cigarette) is also associated with breast cancer.

  5. Environment It is believed that ironizing radiation may be related with breast cancer. For example, the risk is higher if one had breast radiotherapy in youth or in the childhood for other cancer treatment. Environmental pollution is another potential factor though the evidence is not clear yet.

Latest innovations of breast cancer

Apart from the well-established medical background of breast cancer above, OCHIS keeps tracking of the latest innovations in this field, as always.

A research group from Germany has recently demonstrated the urinary microRNAs could be used as new non-invasive biomarkers in early diagnosis of breast cancer. Breast cancer is the most common invasive cancer in women worldwide, causing hundreds of thousands deaths every year. In developing counties including China, it is one of the major public health issues. Currently, mammogram, breast ultrasound and MRI are routinely used in breast cancer screening and diagnosis. Although early detection of breast cancer could be achieved by these imaging modalities, the sensitivity and specificity can be compromised in young women with dense breast tissue. Whereas urinary microRNAs can be utilized to provide sensitive and reliable diagnosis. In this study, the urinary expression levels of nine breast cancer related microRNAs were measured, and four out them were found significantly different in breast cancer patients compared to healthy controls. Using measurements from these microRNAs, high diagnostic accuracies could be achieved with both diagnostic sensitivity and specificity over 90% in testing group. This is the first study revealing the typical microRNA expression patterns in the urine of breast cancer patients. It supports the potential role of urinary microRNAs as non-invasive biomarkers in the early detection of breast cancer, but it is worth noting that large cohort studies are still needed to confirm the findings.

It is difficult to know if and when a cancer patient will relapse. Recently, researchers from The Institute of Cancer Research (ICR) and The Royal Marsden NHS Foundation Trust (both in UK) showed that breast cancer recurrence could be predicted by a "mutation-tracking" blood test. In this study, 55 patients with early-diagnosed breast cancer who had all undergone neoadjuvant chemotherapy before surgery were involved. The clue is to measure circulating tumor DNA (ctDNA) in patients’ blood. The blood samples were taken from these patients every half year for two years to test ctDNA. The results show that patients who tested positive for ctDNA were 12 times more likely to relapse than those who tested negative. Of 15 patients who relapsed, 12 were found to have ctDNA through mutation tracking. The test was capable of predicting the relapse about 8 months before visible signs were picked up by clinics. Dr Nick Peel, from Cancer Research UK, said: "Finding less invasive ways of diagnosing and monitoring cancer is really important and blood samples have emerged as one possible way of gathering crucial information about a patient's disease by fishing for fragments of tumour DNA or rogue cancer cells released into their bloodstream.” "But there is some way to go before this could be developed into a test that doctors could use routinely, and doing so is never simple."

With the advancing and prevalence of breast cancer screening, more early stage breast cancers are diagnosed nowadays. For example, ductal carcinoma in situ (DCIS) is the most common type of non-invasive breast cancer. Although DCIS is not invasive, it can largely increase developing invasive breast cancer possibilities. Then, what should you do if you are diagnosed of early stage DCIS? Many women may choose an aggressive treatment plan like excision surgery to reduce the risk. But it is not an easy decision for women. Furthermore, there has been heated discussion about whether surgery is beneficial or not for low-grade DCIS patients. A recent study published on JAMA Surgery concluded that it is not so beneficial for low-grade DCIS patients to take surgeries than intermediate- or high-grade DCIS, after 57222 DCIS cases. But some specialists argued that there was inherent limitation in this type of study, like different patient and tumor characteristics. A prospective clinical study is needed for confirmation on surgery benefit. It was suggested that feasibly profiling tumor entire genomes could help to understand the relationship between DCIS and invasive breast tumor, so that patients can take targeted therapy approaches.

Another recent study published in The New England Journal of Medicine adopts genetic test to estimate whether chemotherapy is necessary or not for early-stage breast cancer patient. This global study is focused on hormone receptor-positive breast cancer with more than 10,000 patients were included. Receptor-positive breast cancer is the most common breast cancer accounted for two thirds of all breast cancer cases. It is driven by estrogen or progesterone. Patients with early stage receptor-positive breast cancer normally undergo mammectomy followed by chemotherapy and/or hormone therapy to prevent recurrence. In fact, the chemotherapy is not necessary for some low risk patients. However, they are not easy to be reliably distinguished previously. This study utilized a genetic test called Oncotype DX created by Genomic Health, Inc. to analysis 21 breast cancer-related genes and quantified the recurrence risk. Among all the included patients, researchers found 16% were at low-risk, 67 were at intermediate risk and 17 were at high risk according to their scale. Low risked and some intermediate risked patients received hormone therapy only and the remaining intermediate risked patients and high risked patients received hormone therapy and chemotherapy. While the study is still ongoing, the team revealed that around 99% of low risked patients with hormone therapy alone did not experience recurrence within 5 years. In addition, the study also concludes that most early-stage, hormone receptor-positive breast cancer patients may not need chemotherapy. This finding will offer patients great certainty that hormone therapy alone is enough to lower the risk of breast cancer recurrence.

References

[1]http://www.medicalnewstoday.com/articles/300122.php

[2]http://www.innomd.org/index.php?optionid=957&auto_id=5295

[3]https://en.wikipedia.org/wiki/Eidemiologyofbreastcancer#Developingcountries

[4]Erbes, Thalia, et al. "Feasibility of urinary microRNA detection in breast cancer patients and its potential as an innovative non-invasive biomarker." BMC cancer 15.1 (2015): 193. 6/24/2015 Untitled Document

[5]Asaga, Sota, et al. "Direct serum assay for microRNA-21 concentrations in early and advanced breast cancer." Clinical chemistry 57.1 (2011): 84-91.

[6]http://www.medicalnewstoday.com/articles/298690.php

[7]http://www.bbc.com/news/health-34017909

[8] Sagara, Yasuaki, et al. "Survival benefit of breast surgery for low-grade ductal carcinoma in situ: a population-based cohort study." JAMA surgery 150.8 (2015): 739-745.

[9]Margenthaler, Julie A., and Aislinn Vaughan. "No Surgery for Low-Grade Ductal Carcinoma In Situ?." JAMA surgery (2015).

[10]http://www.breastcancer.org/symptoms/types/dcis