TECHNICAL FIELD

The present invention relates to a device and method for cancer detection and diagnosis, and in particular to such device and method for ovarian cancer detection and diagnosis. Moreover, the invention provides efficient cancer screening possibilities.

BACKGROUND

Most cancers can be fatal if detected late. Cancers develop relatively slowly. From the first cancer cell in the body until first symptoms, and clinical diagnosis, usually several years elapse. Cancer diagnosed in the early stages has a much better chance of being cured. For this reason, screening was introduced for several known forms of cancers. The methods available may not always be reliable, whereby only a few screening programs have been set up.

When it comes to gynecological cancers, cervical screening contributes to early diagnosis of cervical cancer and is working well and uterine and vulvar cancers produce symptoms early on. Only for ovarian cancer would there be a need for general screening.

Ovarian cancer is the eighth most common cancer among women worldwide. In Sweden alone, ovarian cancer represents an annual incidence of just under 800 cases. Early discovered (ca. 30% of newly diagnosed ovarian cancers) belong to clinical stages I-II. Patients with such early discovered cancers have relatively good survival prospects. In contrast, about 70% of all newly diagnosed cases belong to stage which means that the survival rate for the patients is low. The overall five-year survival rate is just below 50% (47-48% in Sweden). The latter fact means that more than 400 women die annually from ovarian cancer in Sweden alone.

The survival rate for ovarian cancer patients during the last 10 years has not been improved at all. Biggest problem is the lack of a reliable screening method for early diagnosis. The known and used diagnostic methods such as ultrasound, X-ray, CA-125 analysis (as a tumor marker) all have too low sensitivity and specificity to be used for mass-screening, Due to the high mortality rates of ovarian cancer the disease is highly suitable for screening of healthy populations. A method with sufficient sensitivity and specificity could save hundreds of lives each year in Sweden alone.

The discovery of the specific Volatile Organic Compounds (VOCs) emitted by various cancerous tumors resulted in trials with trained dogs (1), and later with “electronic noses”, to evaluate said dogs and electronic noses as possible diagnostic methods for different cancers. The present inventor demonstrated in several studies that also ovarian cancer cells emit specific VOCs (3). These VOCs can be detected in the patient's blood plasma (4, 5).

The development of so-called nano sensors could possibly be used for the diagnosis of lung cancer through analysis of exhaled air (2). Most substance found in circulating blood can be found also in the breath, albeit in lower concentrations. However, an analysis of exhaled air may be disturbed by various undiagnosed chemical reactions of the oral cavity or pharynx, and/or external agents such as environmental agents and cosmetic preparations.

Small tissue samples were examined by the inventor using a traditional “electronic nose”, based on four TGS sensors. The results showed only very weak signals (6). Consequently, the method using traditional electronic noses is not useful in practice for early diagnosis and screening. That is because the sensitivity of these traditionally built electronic noses in the context of cancer diagnosis is very low. As an example, these noses may not detect VOCs from plasma or blood. Hence, there is a need for improved devices and methods for cancer diagnosis based on VOCs.

