Benefit of PET and PET/CT in ovarian cancer is not proven

August 8, 2012

Due to the lack of studies, there is currently no proof that patients with ovarian cancer can benefit from positron emission tomography (PET) alone or in combination with computed tomography (CT). As regards diagnostic accuracy, in certain cases, recurrences can be detected earlier and more accurately with PET or PET/CT than with conventional imaging techniques. This is the conclusion of the final report by the German Institute for Quality and Efficiency in Health Care (IQWiG) in Cologne that was published on 23 May 2012.

is the fifth most common malignant tumour in women. Every year 15.9 women in every 100,000 are diagnosed with the disease in Germany and it claims the lives of 8 in 100,000 women per year. Since the lie deep in the and an ovarian tumour normally causes no symptoms for a long time, it is often only discovered at a late stage.

Many experts hope that an investigation using PET or PET/CT alone or in combination with other methods would be better able to distinguish between benign and malignant tumours when ovarian cancer is suspected. It could also help classify cancerous tumours into the correct stage, make it easier to assess whether they respond to treatment and to show earlier and with greater certainty whether a recurrence or secondary tumour () has occurred. This information should then enable patients to be given better .

IQWiG therefore searched the international literature for studies investigating the effects of diagnosis using PET or PET/CT on health aspects of direct relevance to patients. For example, the results of this research - and an appropriately tailored treatment - could contribute to patients having better chances of survival, spare them unnecessary operations or other , or improve their quality of life. However, the search for such studies was unsuccessful, so the question as to the patient-relevant benefit of PET or PET/CT had to remain unanswered.

In addition, IQWiG searched for studies in which the and prognostic power of PET or PET/CT were compared with other diagnostic methods. The basic question is how often a PET investigation gives a correct result. On the one hand, it should overlook true, cancerous tumours as rarely as possible, but on the other, it should not awake any false suspicions.

The results of a total of 40 individual studies on this topic were evaluated. However, these studies permit a robust conclusion only in respect of the detection (or exclusion) of a recurrence, where PET or PET/CT appears to be more reliable than other methods. Nevertheless, it remains unclear whether this only applies to patients in whom symptoms (e.g. pain) have already occurred, or also to those in whom routine screening has shown an abnormal blood test result. This is because only very few studies give precise details on this point.

Since even the above patients have not been investigated to determine whether the higher test accuracy of PET or PET/CT has positive effects on mortality, the burden of disease or the quality of life, IQWiG assumes that a patient-relevant benefit of PET or PET/CT is not proven. For instance, it is particularly questionable whether a detected by PET or PET/CT can actually be better treated - and the patient thereby has a noticeable advantage.

It is therefore essential that doctors fully inform their patients not only of the possible benefits in the form of an earlier diagnosis, but also of the possible harms. The latter can arise from an earlier start to second-line treatment associated with considerable side effects, but not with a prolongation of survival. Hence studies are urgently needed to investigate the patient-relevant benefit of PET or PET/CT in the diagnosis of ovarian cancers in direct comparison with conventional diagnostic techniques.

Explore further: Benefit of PET in patients with head and neck tumors cannot be assessed

Related Stories

Benefit of PET in patients with head and neck tumors cannot be assessed

April 29, 2011
The benefit and harm of positron emission tomography (PET) in patients with head and neck tumours, applied alone or in combination with computed tomography (CT), cannot currently be reliably assessed. This is the result of ...

Routine follow-up scans can detect head and neck cancer recurrences earlier

January 26, 2012
Routine use of positron emission tomography/computed tomography (PET/CT) scans in head and neck cancer patient follow-up can detect local recurrences before they become clinically apparent and may improve the outcome of subsequent ...

Life expectancy prolonged for esophageal cancer patients

June 4, 2012
For those with esophageal cancer, initial staging of the disease is of particular importance as it determines whether to opt for a curative treatment or palliative treatment. Research presented in the June issue of The Journal ...

Recommended for you

Study provides insight into link between two rare tumor syndromes

August 22, 2017
UCLA researchers have discovered that timing is everything when it comes to preventing a specific gene mutation in mice from developing rare and fast-growing cancerous tumors, which also affects young children. This mutation ...

Retaining one normal BRCA gene in breast, ovarian cancers influences patient survival

August 22, 2017
Determining which cancer patients are likely to be resistant to initial treatment is a major research effort of oncologists and laboratory scientists. Now, ascertaining who might fall into that category may become a little ...

Study identifies miR122 target sites in liver cancer and links a gene to patient survival

August 22, 2017
A new study of a molecule that regulates liver-cell metabolism and suppresses liver-cancer development shows that the molecule interacts with thousands of genes in liver cells, and that when levels of the molecule go down, ...

Zebrafish larvae could be used as 'avatars' to optimize personalized treatment of cancer

August 21, 2017
Portuguese scientists have for the first time shown that the larvae of a tiny fish could one day become the preferred model for predicting, in advance, the response of human malignant tumors to the various therapeutic drugs ...

Scientists discover vitamin C regulates stem cell function, curbs leukemia development

August 21, 2017
Not much is known about stem cell metabolism, but a new study from the Children's Medical Center Research Institute at UT Southwestern (CRI) has found that stem cells take up unusually high levels of vitamin C, which then ...

Searching for the 'signature' causes of BRCAness in breast cancer

August 21, 2017
Breast cancer cells with defects in the DNA damage repair-genes BRCA1 and BRCA2 have a mutational signature (a pattern of base swaps—e.g., Ts for Gs, Cs for As—throughout a genome) known in cancer genomics as "Signature ...

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.