her2+ breast cancer may be less common than previously quoted

[Lani]

I previously quoted a study from the Hawaii tumor registry with 11% her 2 positivity, here is a study from Sweden looking into whether their her2 testing is reproducible across the country showing a 14% incidence.

In the review article I posted on 10 years of targetted her2 therapy, they noted that it will probably turn out that her2+ breast cancer is quite a bit less
prevalent than previously quoted ie, 20-25%.

[Hopeful]

Lani,

If you meant to include a link to the Sweden study in your post, it is missing.

Standardized testing (or the lack thereof) has been an issue for not just Her2 but other prognostic factors, as well, leading to uncertainty about the true prevalance of Her2+ bc. What will be enlightening, IMO, will be the results following the application of more accurate methods and uniform testing standards on a going-forward basis.

Hopeful

[Rich66]

Just posted in Articles

[Lani]

Acta Oncol. 2009 Apr 7:1-7. [Epub ahead of print]
Reproducibility of human epidermal growth factor receptor 2 analysis in primary breast cancer - A national survey performed at pathology departments in Sweden.

Ryden L, Haglund M, Bendahl PO, Hatschek T, Kolaric A, Kovacs A, Olsson A, Olsson H, Strand C, Ferno M.
Department of Surgery, University Hospital, Lund, Sweden.
Background. HER2 is a treatment predictive factor for the effect of trastuzumab and associated with poor prognosis in breast cancer. The analysis of HER2 must be performed with good quality, with regard to both the immunohistochemical (IHC) and in situ hybridization (ISH) analysis. Material and methods. A tissue microarray (TMA) including 11 breast cancer samples was sent twice (once in 2005 and again in 2006) to 24 pathology departments in Sweden. A questionnaire was also sent to the departments in 2006. Results. With IHC, all departments reported the same results (0/1+ vs. 2+ vs. 3 + ) for three (2005) and six samples (2006). The mean kappa-value increased from 0.67 to 0.77, indicating a good reproducibility at both occasions. With fluorescence-ISH (FISH), the 11 departments using this technique reported the same results (amplified vs. normal) for nine (2005) and ten samples (2006). The mean kappa-value showed very good reproducibility both 2005 and 2006 (0.92 and 0.96, respectively). Based on the answers from the participating departments, the questionnaire revealed that 31% of primary breast cancer diagnosed in 2006 (n = 5 043) were 2+ /3+ . FISH analysis of 2+ confirmed 12% of the samples to be amplified. The corresponding figure for 3 + was 90%. In total, 14.3% of the samples were HER2 positive (2+ and amplified, or 3 + ). Discussion. The results obtained in this study indicate that the reproducibility for HER2 analysis is good (IHC) and very good (FISH) between the pathology departments in Sweden using TMA-based tumor samples. In 2006, 14.3% of invasive breast cancers were HER2 positive.
PMID: 19353340

[Brenda_D]

That makes sense to me. In the last 2 years I ran across lots of ladies with BC and only 1 that was her2 + like me. She only knew of one other lady too.

[Joe]

I really wouldn't put much credence in this report as the study group was composed primarily of one racial group.

Incidences of breast cancer varies among ethnicities and diet. The study sample was also small.

Regards
Joe

[Lani]

of MD Anderson think differently:

from their article--

HER-2 Positivity Rates

The frequency of HER-2 positivity in all of the studies pre-
sented in Table 1 was 22.2%, with a range of 9%–74%. The
HER-2–positive rate was similar for IHC, at 22% (range,
10%–74%), and FISH, at 23.9% (range, 14.7%– 68%). In
current practice, HER-2–positive rates have trended below
20%, with most investigators currently reporting that the
true positive rate is in the range of 15%–20%. The HER-2–
positive rate may be higher when metastatic lesions are
tested, and tertiary hospitals and cancer centers report
slightly higher rates than community hospitals and national
reference laboratories.

reference:
www.TheOncologist.com
The HER-2 Receptor and Breast Cancer: Ten Years of Targeted
Anti–HER-2 Therapy and Personalized Medicine
JEFFREY S. ROSS,a ELZBIETA A. SLODKOWSKA,a W. FRASER SYMMANS,b LAJOS PUSZTAI,b
PETER M. RAVDIN,b GABRIEL N. HORTOBAGYI,
Department of Pathology and Laboratory Medicine, Albany Medical College, Albany, New York, USA;

Departments of Pathology, Breast Medical Oncology, and Biostatistics and Quantitative Sciences, The
University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA

The Hawaii study was relatively small, but about as ethnically mixed as you can get!

The Swedish study included 5 043 patients and in several parts of southern Sweden over 70% of the population comes
from other countries including a large contingent from the Middle East and Africa. Sweden is no longer as ethnically homogenous as it used to be!

From Wikipedia--
From the late 1940s and until 1973 work-force immigration dominated, peaking in the late 1960s. Finns make up about 5% of the whole population. The occupant population of northern Sweden, the Sami people, (a ethnic group living in 4 countries) is only about 20,000 persons.
The largest immigrant groups in Sweden are Finns, Assyrians/Syriacs, Russians from the former USSR (including Ukrainians and Russian Jews), Turks from Turkey and Cyprus, Greeks from Greece and Cyprus, Albanians from Albania and the Republic of Macedonia, and South Slavic peoples from the former Yugoslavia (namely Serbia, Croatia, and Bosnia and Herzegovina) representing both work-force immigration and war refugees.
Migration triggered by political crises and economic disparities in the second half of the 20th century include refugee groups of Assyrians/Syriacs from Syria, Turkey, Lebanon and Iraq; Persians; Kurds from Iraqi Kurdistan and Turkey; Palestinians; Koreans from South Korea and Manchuria, China; Filipinos; Vietnamese; Argentinans; Baluchis from Pakistan; Moroccans; Spaniards; Sicilians from Italy; Hungarians; and Chileans.
Sweden has taken in refugees from various countries fleeing persecution, including people from the former East Germany, Poland, Iran, Myanmar, Vietnam, Nicaragua and Guatemala; and more recently from conflict-zones in the former Yugoslavia, Chechnya, Libya, Iraq, Lebanon, Afghanistan and Somalia.
In fact, Sweden has a history of providing refuge to asylum seekers. On a smaller scale, it took in political refugees from Hungary and the former Czechoslovakia after their countries were invaded by the Soviet Union in 1956 and 1968 respectively. Some tens of thousands of American draft dodgers from the Vietnam War in the 1960s and 1970's also found refuge in Sweden.
Today, Sweden has one of the largest exile communities of Assyrians/Syriacs.
A sizable community from the Baltic States (Estonia, Latvia and Lithuania) arrived during the Second World War.[6]